Leviticus 23:11

and he shall uplift the sheaf before the Lord to be accepted for you. After the first festal day of Pascha (or, the day after the feast-day of Pascha)

the day after the day of rest [literally: the day after the Sabbath] Our Sages, of blessed memory, have said [Menaḥot 65b] that this denotes the second day of the festival; the Dissenters maintain that the verse should be taken literally. The faithful bring examples from the Sabbatical Year [25:2], the Jubilee, Yom Kippur [:32], and the New Year [:24], all of which are called “sabbath”. The first and the eighth days of Sukkot are called “sabbath” [:39], too [see also comment on Exodus 31:13]. Moreover, a “sabbath” also means a “week”, as in “seven sabbaths” [:15] as well as “those who came in on the Sabbath, along with those who had finished for the week” [II Kings 11:9] (where one verse uses two different meanings of the same word ). In addition to these definitive arguments, Meshullam ben Qalonymus of Rome attempted to bring a proof from “…on the day after the Passover, maṣṣot and toasted grain” [Joshua 5:11] without realizing that he thereby weakened his own argument. The Passover sacrifice occurs on the fourteenth of the month; the day after the Passover sacrifice is the first day of the festival, as it is written: “They marched from Rameses, in the first month, on the fifteenth day of the first month, the day after the Passover” [Numbers 33:3]. However, the eating of parched grain is forbidden until after the ‘Omer-offering has been waved! To resolve this, Sa‘adya Gaon proposed 1) that there are two Passovers: the first is Israel’s Passover, while the second is God’s Passover, and is observed on the evening of the fifteenth. Thus, the reference to “the day after Passover” in Joshua is a reference to the sixteenth of the month, but the reference to “the day after Passover” in the Torah denotes the day after the Passover sacrifice . This explanation is unsatisfactory, because the Passover festival owes its name to God’s passing over our houses. “The day after” that event denotes the following morning — which is still the fifteenth (compare, “…the entire day, the entire night, and the entire day after” [Numbers 11:32]). 2) Sa‘adya Gaon also suggested that the “maṣṣot and toast” were from the previous year’s crop, which makes sense. Scripture says that the waving of the ‘Omer offering takes place “from the time when you begin to reap the grain” [Deuteronomy 16:9]. If the waving of the ‘Omer that year occurred on the fifteenth, when did they have time to harvest the grain and prepare maṣṣot? Even if they had had the …

ON THE MORROW AFTER ‘HA’SHABBATH’ THE PRIEST SHALL WAVE IT. “That is, the morrow after the first day of the Festival of Passover. For if you are to say it means [on the morrow of] the Sabbath of Creation [i.e., the weekly Sabbath], you have no indication which Sabbath is meant.” This is Rashi’s language. And indeed, this is the greatest of the proofs mentioned in the Gemara [to show that ha’shabbath here is not to be interpreted literally as meaning the weekly Sabbath, but refers to the first day of Passover]; for what sense is there for Scripture to state that “when ye are to come into the Land … and shall reap the harvest thereof ye shall bring the sheaf on the morrow of the weekly Sabbath,” which would mean that at any time of the year when we come into the Land and reap its harvest, the priest shall wave the sheaf on the morrow of the first Sabbath after we have come into the Land! In that case the Festival of Weeks would have no [definite] starting point from which we are to count [the forty-nine days, so that on the fiftieth day we should celebrate that festival]! Moreover, according to this way we would not know even in the years following [our entrance into the Land] when we are to begin counting [the forty-nine days], but only from the day that we first put the sickle to the standing grain at our will. But these are meaningless words! If, however, the expression on the morrow after ‘ha’shabbath’ means “on the morrow after [the first day of] the festival,” in accordance with the tradition of our Rabbis, then the matter appears correctly. For at first Scripture commanded that we should observe in the first month the Festival of Unleavened Bread for seven days, and that on the first day there should be a solemn rest and on the seventh day a solemn rest, and we are not to do thereon any manner of servile work. Afterwards He stated that when we come into the Land we are to bring on the morrow of this rest-day [previously] mentioned, the sheaf of the waving, this being the first rest-day here mentioned. And He also taught that the [bringing of the] sheaf was not obligatory in the desert, nor outside the Land [since the section begins, When ye are come into the Land …]. However, the expressions, even unto the morrow after ‘ha’shabbath’ the seventh and seven ‘shabbathoth’ cannot possibly be interpreted as referring to a festival [as does the expression on the morrow after ‘ha’shabbath’ here in Verse …

ממחרת השבת, on the day following the first day of the Passover festival.