There are at least six different approaches to understanding the term "morrow of the Shabbat." One, the traditional view is that it means the day after the first day of chag ha-matzot, the 16th of Nisan. (In the Diaspora, this is the second day of Yom Tov, and in Israel the first day of chol ha-moed of Pesach.)
Two, the view of the Karaites, and possibly of the Boethusians, a sect in the time of the second Bet ha-Mikdash, that it means, the Sunday after the Saturday within chag ha-matzot. (If Pesach started on Saturday, then the Karaites, held the day was the second day of Pesach just like the traditional view.)
Three, Shmuel Sprecher (1993) has suggested that the Boethusians held that the omer was brought on the second day of chag ha-matzot like the traditional view, but the count started on the Sunday after the Saturday within chag ha-matzot.
Four, the omer was brought on the day after the last day of chag ha-matzot. (Apparently, this was the practice of Ethiopian Jews. David Hoffmann, 1953, vol.2, pp. 124-127, quotes several scholars who hold this view and claims that this is the view of the Targum Peshitta. However, Yeshayahu Maori (1995, pp. 176-178) claims the Peshitta follows the traditional view.)
Five, the book of Jubilees, the Dead Sea Scrolls, and possibly the view of the Boethusians, the omer was to be brought on the first Sunday after chag ha-matzot.
Six, the omer was brought on the first Sunday after the first reaping with no connection with chag ha-matzot.
The Talmud (Menahot 65a-66a) quotes many arguments for the traditional approach, but perhaps the most convincing proof is not mentioned in the Talmud. Yehoshua 5:11 records that when the Jewish people first came into the land of Israel even before the battle of Jericho, they ate bread and wheat on the day after the pesach sacrifice (see Rambam, Laws of regular and extra sacrifices, 7:8-10, and Hoffmann, pp. 134-136). The proof is that Vayikra 23:14 only allows one to eat the new grains after the omer sacrifice was brought, and in Yehoshua 5:11 it appears that the people ate the new wheat on the day after the pesach sacrifice, which means the omer was brought on the day after the pesach sacrifice.
This proof has several problems and it is telling that the Talmud did not mention it. One, according to Yehoshua 5:10, the pesach sacrifice was brought on the 14th of Nisan, which means the day after the sacrifice was the 15th of Nisan, and this does not match up with the traditional view, which is that the omer is to be brought on the 16th of Nisan. Two, Yehoshua 5:11,12 does not state that the people ate new grains, rather that they ate grains from the land of Israel and not the mahn. Three, the book of Yehoshua makes no mention that the people celebrated chag ha-matzot that year, and hence maybe that year was a special circumstance since there was only the pesach sacrifice. (On the other hand, if one claims that pesach also means chag ha-matzot, as is the common language today, then the day after pesach could be the day after chag ha-matzot, which is the fourth view.) Four, the case is unique for another reason. Usually people have old grain stored up, but presumably when the people just came to the land of Israel, they had no supplies of grain, and hence maybe once the mahn stopped, they had to be allowed to eat even new grain immediately.
The order of the festivals in chapter 23 strongly implies that the omer offering was to be brought after chag ha-matzot. In the chapter, the Torah first records the festival of chag ha-matzot and then the bringing of the omer sacrifice.
In addition, in chapter 23, each festival is separated in the chapter by the verse, "G-d spoke to Moshe." Yet, with regard to the holiday of Shavuot there appears to be anomaly since this phrase does not appear by 23:15, which apparently begins the discussion of the laws of the day of Shavuot. N. Leibowitz (1980, pp. 218-223) quotes the Talmud and the Hinukh that there is no separating verse for Shavuot since Shavuot is a continuation of the holiday of Matzot since the goal of the exodus from Egypt was to receive the Torah at Mount Sinai. Yet, chapter 23 never alludes to the fact that the Torah was given on Shavuot. Furthermore, the phrase “G-d spoke to Moshe” appears between the laws of Pesach and the laws of Shavuot as it occurs prior to the verses that record the law of bringing the omer, 23:9.
The phrase "G-d spoke to Moshe" in 23:9 signals the beginning of the holiday of Shavuot. The holiday is a fifty day holiday, and only the last day is a mikra kodesh that one is forbidden to work, 23:21. The holiday starts with the bringing of the omer and after seven full weeks, it ended with the bringing of the two loaves. Shemot 23:16 refers to the holiday as one of reaping, and this reaping is referred to in Vayikra 23:10 by the bringing of the omer, which is the beginning of the festival. This idea accords with the name Shavuot a feast of weeks, as the holiday was for seven weeks. Similarly, Bemidbar 28:26 and Devarim 16:9-12 when discussing the festival of Shavuot refers to weeks prior to the day of Shavuot, again because the holiday is for fifty days. This understanding nullifies the first three explanations of the term "on the morrow" since it cannot be that the fifty day holiday of Shavuot started in the middle of the holiday of matzot.
This same idea that the fifty days of Shavuot begins after chag ha-matzot is evident in Devarim 16. Devarim 16:1-8 records laws of the holiday of Pesach and of the chag ha-matzot, and it refers to the second mikrei kodesh of chag ha-matzot. Afterwards, Devarim 16:9 records that one is to start counting the seven weeks. The implication is that the counting is only to begin after the chag ha-matzot ended.
I think the fourth view is correct that the phrase "on the morrow" refers to the day after chag ha-matzot. In the end of 23:15, the word shabbat means week, seven weeks. This suggests that the word shabbat in the beginning of 23:15 also means week, the morrow after the week. What week is being referred to? The week of chag ha-matzot. 23:11 then means that the omer is to be brought on the day after the end of the week of chag ha-matzot. Finally, the word shabbat in 23:16 also means week, "Until the morrow after the seventh week, you shall count fifty days."
Why did the Torah not then clearly state that that the omer is to be brought on the day after chag ha-matzot? One possibility is that really the word shabbat means a period of time when one is to rest, and while usually this is Saturday, really it can be a longer period of time, like a week. With this idea, the word shabbat does not necessarily refer to Saturday, and can just as equally refer to a festival. A second possibility is that the Torah did not want to connect Shavuot with chag ha-matzot. Chag ha-matzot is a historical holiday, while Shavuot is an agricultural holiday. If the bringing of the omer was recorded in reference to chag ha-matzot, this might have caused one to think that chag ha-matzot was an agricultural holiday, but really the holiday is only to recognize that G-d took the Jewish people out of Egypt. A third possibility is that the use of the word shabbat in conjunction with mimaharet is to re-enforce the sabbatical theme of the shabbatot of the weeks.
My guess is that the traditional approach to understanding the term "on the morrow" as being the 16th of Nisan is because Chazal deliberately moved up the counting of the omer six days in order to make the holiday of Shavuot closer to the day of the Decalogue. In the Torah there is no connection at all between Shavuot and the Decalogue, but Chazal wanted to make this connection. (This connection occurs in the book of Jubilees.) If the counting of the omer starts after chag ha-matzot, the 22nd of Nisan, then Shavuot would be celebrated on the 12th of Sivan, but if the counting of the omer starts on the 16th of Nisan, then Shavuot is on the sixth day of Sivan.
It is not obvious in the Torah on which day the Decalogue occurred. Shemot 19:1 records that the Jewish people came to Mount Sinai on the third month (Sivan) and the verse seems to be referring to the first day of the month. Afterwards, there are several conversations between G-d and Moshe and it is not clear when they took place, on one day or spread out over several days. Shemot 19:10 records the next explicit reference to time that the Decalogue would take place three days later, which at a minimum was the third day of Sivan. However, in the Talmud (Shabbat 86b) the Rabbis maintained that each conversation between G-d and Moshe occurred on a separate day, and then the Decalogue was either on the sixth or seventh of Sivan.
The Tosefta, Erechin 1:4, and Talmud Rosh Hashanah 6b, note that in the time when the calendar was determined by sight, the holiday of Shavuot was celebrated on either the fifth, sixth or seventh of Sivan depending on the length of the months of Nisan and Iyar, see Henshke, 1992, pp. 441-444. This means that even if the omer was offered on the 16th of Nisan, still Shavuot was sometimes celebrated near the date of the Decalogue but not always on the day of the Decalogue,
My guess is that Chazal moved up the omer offering to have Shavuot be close to the day when they thought that the Decalogue occurred. They could not get it exact since the lengths of the months were not exact, but they could make the two events close. When the calendar and the months were fixed, then they could get them to be exact, but this also took to interpreting Shemot 19 to mean that the Decalogue was on the sixth of Sivan. The jump of moving the counting of the omer a week earlier was not so ground-breaking since according the fourth view, the day of the morrow was the day after the last day of chag ha-matzot, while now it would be the day after the first day of chag ha–matzot. Finally, according to the Mishnah (Rosh Hashanah 2:10) and the Talmud (Pesachim 117b and Berakhot 49a), Chazal have the power to decide when a holiday is celebrated, and hence they can decide to celebrate Shavuot a week earlier on the sixth of Sivan instead of the twelfth of Sivan.
The Talmud (Menahot 65a-66a) quotes many arguments for the traditional approach, but perhaps the most convincing proof is not mentioned in the Talmud. Yehoshua 5:11 records that when the Jewish people first came into the land of Israel even before the battle of Jericho, they ate bread and wheat on the day after the pesach sacrifice (see Rambam, Laws of regular and extra sacrifices, 7:8-10, and Hoffmann, pp. 134-136). The proof is that Vayikra 23:14 only allows one to eat the new grains after the omer sacrifice was brought, and in Yehoshua 5:11 it appears that the people ate the new wheat on the day after the pesach sacrifice, which means the omer was brought on the day after the pesach sacrifice.
This proof has several problems and it is telling that the Talmud did not mention it. One, according to Yehoshua 5:10, the pesach sacrifice was brought on the 14th of Nisan, which means the day after the sacrifice was the 15th of Nisan, and this does not match up with the traditional view, which is that the omer is to be brought on the 16th of Nisan. Two, Yehoshua 5:11,12 does not state that the people ate new grains, rather that they ate grains from the land of Israel and not the mahn. Three, the book of Yehoshua makes no mention that the people celebrated chag ha-matzot that year, and hence maybe that year was a special circumstance since there was only the pesach sacrifice. (On the other hand, if one claims that pesach also means chag ha-matzot, as is the common language today, then the day after pesach could be the day after chag ha-matzot, which is the fourth view.) Four, the case is unique for another reason. Usually people have old grain stored up, but presumably when the people just came to the land of Israel, they had no supplies of grain, and hence maybe once the mahn stopped, they had to be allowed to eat even new grain immediately.
The order of the festivals in chapter 23 strongly implies that the omer offering was to be brought after chag ha-matzot. In the chapter, the Torah first records the festival of chag ha-matzot and then the bringing of the omer sacrifice.
In addition, in chapter 23, each festival is separated in the chapter by the verse, "G-d spoke to Moshe." Yet, with regard to the holiday of Shavuot there appears to be anomaly since this phrase does not appear by 23:15, which apparently begins the discussion of the laws of the day of Shavuot. N. Leibowitz (1980, pp. 218-223) quotes the Talmud and the Hinukh that there is no separating verse for Shavuot since Shavuot is a continuation of the holiday of Matzot since the goal of the exodus from Egypt was to receive the Torah at Mount Sinai. Yet, chapter 23 never alludes to the fact that the Torah was given on Shavuot. Furthermore, the phrase “G-d spoke to Moshe” appears between the laws of Pesach and the laws of Shavuot as it occurs prior to the verses that record the law of bringing the omer, 23:9.
The phrase "G-d spoke to Moshe" in 23:9 signals the beginning of the holiday of Shavuot. The holiday is a fifty day holiday, and only the last day is a mikra kodesh that one is forbidden to work, 23:21. The holiday starts with the bringing of the omer and after seven full weeks, it ended with the bringing of the two loaves. Shemot 23:16 refers to the holiday as one of reaping, and this reaping is referred to in Vayikra 23:10 by the bringing of the omer, which is the beginning of the festival. This idea accords with the name Shavuot a feast of weeks, as the holiday was for seven weeks. Similarly, Bemidbar 28:26 and Devarim 16:9-12 when discussing the festival of Shavuot refers to weeks prior to the day of Shavuot, again because the holiday is for fifty days. This understanding nullifies the first three explanations of the term "on the morrow" since it cannot be that the fifty day holiday of Shavuot started in the middle of the holiday of matzot.
This same idea that the fifty days of Shavuot begins after chag ha-matzot is evident in Devarim 16. Devarim 16:1-8 records laws of the holiday of Pesach and of the chag ha-matzot, and it refers to the second mikrei kodesh of chag ha-matzot. Afterwards, Devarim 16:9 records that one is to start counting the seven weeks. The implication is that the counting is only to begin after the chag ha-matzot ended.
I think the fourth view is correct that the phrase "on the morrow" refers to the day after chag ha-matzot. In the end of 23:15, the word shabbat means week, seven weeks. This suggests that the word shabbat in the beginning of 23:15 also means week, the morrow after the week. What week is being referred to? The week of chag ha-matzot. 23:11 then means that the omer is to be brought on the day after the end of the week of chag ha-matzot. Finally, the word shabbat in 23:16 also means week, "Until the morrow after the seventh week, you shall count fifty days."
Why did the Torah not then clearly state that that the omer is to be brought on the day after chag ha-matzot? One possibility is that really the word shabbat means a period of time when one is to rest, and while usually this is Saturday, really it can be a longer period of time, like a week. With this idea, the word shabbat does not necessarily refer to Saturday, and can just as equally refer to a festival. A second possibility is that the Torah did not want to connect Shavuot with chag ha-matzot. Chag ha-matzot is a historical holiday, while Shavuot is an agricultural holiday. If the bringing of the omer was recorded in reference to chag ha-matzot, this might have caused one to think that chag ha-matzot was an agricultural holiday, but really the holiday is only to recognize that G-d took the Jewish people out of Egypt. A third possibility is that the use of the word shabbat in conjunction with mimaharet is to re-enforce the sabbatical theme of the shabbatot of the weeks.
My guess is that the traditional approach to understanding the term "on the morrow" as being the 16th of Nisan is because Chazal deliberately moved up the counting of the omer six days in order to make the holiday of Shavuot closer to the day of the Decalogue. In the Torah there is no connection at all between Shavuot and the Decalogue, but Chazal wanted to make this connection. (This connection occurs in the book of Jubilees.) If the counting of the omer starts after chag ha-matzot, the 22nd of Nisan, then Shavuot would be celebrated on the 12th of Sivan, but if the counting of the omer starts on the 16th of Nisan, then Shavuot is on the sixth day of Sivan.
It is not obvious in the Torah on which day the Decalogue occurred. Shemot 19:1 records that the Jewish people came to Mount Sinai on the third month (Sivan) and the verse seems to be referring to the first day of the month. Afterwards, there are several conversations between G-d and Moshe and it is not clear when they took place, on one day or spread out over several days. Shemot 19:10 records the next explicit reference to time that the Decalogue would take place three days later, which at a minimum was the third day of Sivan. However, in the Talmud (Shabbat 86b) the Rabbis maintained that each conversation between G-d and Moshe occurred on a separate day, and then the Decalogue was either on the sixth or seventh of Sivan.
The Tosefta, Erechin 1:4, and Talmud Rosh Hashanah 6b, note that in the time when the calendar was determined by sight, the holiday of Shavuot was celebrated on either the fifth, sixth or seventh of Sivan depending on the length of the months of Nisan and Iyar, see Henshke, 1992, pp. 441-444. This means that even if the omer was offered on the 16th of Nisan, still Shavuot was sometimes celebrated near the date of the Decalogue but not always on the day of the Decalogue,
My guess is that Chazal moved up the omer offering to have Shavuot be close to the day when they thought that the Decalogue occurred. They could not get it exact since the lengths of the months were not exact, but they could make the two events close. When the calendar and the months were fixed, then they could get them to be exact, but this also took to interpreting Shemot 19 to mean that the Decalogue was on the sixth of Sivan. The jump of moving the counting of the omer a week earlier was not so ground-breaking since according the fourth view, the day of the morrow was the day after the last day of chag ha-matzot, while now it would be the day after the first day of chag ha–matzot. Finally, according to the Mishnah (Rosh Hashanah 2:10) and the Talmud (Pesachim 117b and Berakhot 49a), Chazal have the power to decide when a holiday is celebrated, and hence they can decide to celebrate Shavuot a week earlier on the sixth of Sivan instead of the twelfth of Sivan.
Henshke, David, 1992, The history of the counting of the omer, in Rabbi Mordechai Breuer Festchrift, edited by Moshe Bar-Asher, Jerusalem: Academon Press, pp. 417-448.
Hoffmann, David (1843-1921), 1953, Leviticus, Jerusalem: Mossad Harav Kook.
Leibowitz, Nehama (1905-1997), 1980, Studies in Vayikra, translated by Aryeh Newman, Jerusalem: The World Zionist Organization.
Maori, Yeshayahu, 1995, The Peshitta version of the Pentateuch and early Jewish exegesis, Jerusalem: Magnes Press.
Sprecher, Shmuel, 1993, "The offering of the omer and counting of the omer: The view of the Boethusians," Sidra, 9, pp. 105-116.
Sprecher, Shmuel, 1993, "The offering of the omer and counting of the omer: The view of the Boethusians," Sidra, 9, pp. 105-116.