Comentario citado sobre Levítico 23:8

KEEP THE MONTH OF AVIV. The commandment of the festivals [mentioned here] is explanatory, for He has already mentioned it. Now, in the Book of Leviticus He mentioned with reference to the festivals, And ye shall bring an offering made by fire unto the Eternal,³¹⁴Leviticus 23:8. but here he did not mention them [the offerings] at all. Instead he commanded Israel to ascend on their account [to celebrate the festivals] to the place which He will choose, and rejoice before Him. For just as he commanded that one bring the Second Tithe before G-d,³¹⁵Above, 14:23. and also the firstling,³¹⁶Ibid., 15:19. and eat them there in the place that G-d will choose, he added [here] to make it clear that they will all be further obligated to come before G-d and celebrate before Him on three festivals and rejoice with the peace-offerings that they will offer before Him. Now he did not mention the times of the Festivals of Unleavened Bread and Tabernacles on which dates they occur, but he briefly mentioned their months, for He had already stated everything there.³¹⁷Leviticus 23:4-43.

ממחרת הפסח, “on the morning following the offering (and consuming) of the Passover sacrifice.” Both Passover eve and the first night are called פסח, because these are the periods the people are preoccupied with the Passover offering. If we needed proof for this, we only have to look at Leviticus 23,8 and Numbers 28,16. The remainder of that festival is always referred to as חג המצות, “the festival of unleavened breads.”

מקרא קדש — This means: Hallow it (make it different from other days) by wearing fine clothes, and through appropriate prayer. In the case of other Festivals of which the same words are used, the expression מקרא קדש implies: Hallow them (distinguish them from other days) by your food and drink, by your fine clothes and appropriate prayers (cf. Sifra, Emor, Section 12 4).