(1) The commandment of counting the omer: To count forty-nine days from the bringing of the omer which is on the sixteenth day of Nissan, as it is stated (Leviticus 23:15), “And you shall count for yourselves from the morrow of the Shabbat from the day of your bringing the omer of waving.”

And this counting is an obligation, and it is upon us to count the days on each day and, likewise, the weeks. As Scripture said to count fifty days and also said (Deuteronomy 16:9), “Seven weeks shall you count for yourself.” And in explanation, Abbaye said in the Gemara in Menachot 66a, “It is a commandment to count the days and it is a commandment to tally the weeks.” (See Sefer HaMitzvot, Positive Commandments 161.)

(3) It is from the roots of the commandment from the angle of the simple understanding [that it is] since the entire essence of Israel is only the Torah, and because of the Torah were the heavens and earth created, and as it is stated (Jeremiah 33:25), “Were it not for my covenant day and night, etc.”

And it is the essence and the reason that they were redeemed and left from Egypt — in order that they receive the Torah at Sinai, and fulfill it. And [it is] like God said to Moshe (Exodus 3:12), “And this will be the sign for you that I have sent you; when you take out the people from Egypt, you shall worship God on this mountain.” And the understanding of the verse is [that] your taking them out from Egypt is a sign for you that you shall worship God on this mountain — meaning that you shall receive the Torah, which is the great principle for which they were redeemed and it is their ultimate good. And it is a great matter for them, more than freedom from slavery. And hence God made a sign of their leaving Egypt for the receiving of the Torah; as we always make what is secondary into a sign for what is the essence.

(4) And because of this — that it is [the] essence of Israel, and because of it were they redeemed and went up to all of the greatness to which they rose — we were commanded to count from the day after the holiday of Pesach until the day of the giving of the Torah; to show about ourselves the great desire [we have] for the honored day, which our hearts yearn [for] like “a slave seeks shade” and always counts when will come the yearned-for time that he goes out to freedom. As the count shows about a man that all of his deliverance and all of his desire is to reach that time. And that which we count to the omer, meaning, “Such-and-such days have passed from the count,” and we do not count “Such-and-such days do we have to the time,” is because all of this shows us the great desire to reach the time [of Shavuot]. Therefore, we do not want to mention at the beginning of our counting the large number of days that we have to reach the offering of the two breads of [Shavuot]. And let it not be difficult for you, to say, “If so, after most of the days of these seven weeks have passed, why do we not mention the minority of the remaining days?” [It is] as one should not change the nature of the counting in the middle. And if you shall ask, “If so, why do we begin counting from the day after [Pesach] and not from the first day?” The answer [is that] it is because the first day is entirely dedicated to remembering the great miracle, which is the exodus from Egypt, that is a sign and a proof of the world having been created and of God’s — may He be blessed — providence over people. And we may not mix [something else into] its joy and mention anything else with it. And as such, the counting begins immediately from the second day. And we should not say, “Today is such-and-such days from the second day of Pesach” — as the count would not be fitting to say, “From the second day.” And therefore it was ordained to count the tally from that which is done on it — and this is the omer-offering, which is a significant sacrifice. As through it is the remembrance that we believe that God, blessed be He, wants — through His providence over people — to sustain them and [so] renews for them the seed of the grains in each and every year, to live through them.

Seven weeks count for yourself; from the time the sickle begins felling the standing grain, begin to count seven weeks.

You shall count for yourselves, from the day after the day of rest (Pesach) from the day on which you will bring the omer offering, seven complete weeks they shall be,

Until the day after the seventh week, you shall count fifty days, and you shall bring a new meal-offering to Hashem.

From [the land of] your dwelling places you shall bring two bread wave-offerings; of two tenths of flour they shall be. You shall bake them leavened, as first-fruit-offering to Hashem.