Pesach Sh’hayo avotaynu, The Pesach which our ancestors ate when the Temple was still standing: The verse prior to: “You shall say: It is a Passover offering for the Lord…” says, “And when your children ask you: What mean you by this rite.” The fact that the Torah doesn’t preface the answer to this question with, “And you shall say to your children,” or “And you shall say to them,” as in the case of the answers to the other children, suggests that one must ask this question and answer it even without the children’s questions. That is why we begin by asking “The Passover offering for what reason,” and then go on to say, “Because the Holy One passed over the houses of the Israelites…” The Maggid then quotes this verse as a proof text for this statement: “You shall say, ‘It is a Passover offering for Adonai who passed over the houses of the Israelites in Egypt and struck down the Egyptians and spared our houses.’” Note that in the proof text the article et appears before both statements - “struck down (et) the Egyptians” and “spared (et) our houses.” This word comes to teach us that a first born Egyptian in an Israelite house was still stricken during the tenth plague and conversely, an Israelite in an Egyptian house was spared! Even though we have already learned this from the verse, “So that no plague will destroy you when I strike the Land of Egypt,” it is added again here to teach us that we must inform the child of all these details in telling him the story of the Exodus. There is a surprising explanation of this verse by the author of the Korban Pesach Commentary. He explains that we learn from the verse, “You shall say, It is a (pesach) Passover offering for Adonai who passed over the houses of the Israelites in Egypt” that one should begin studying the laws of Passover thirty days before the festival. He deduces this in the following way: half the numerical value of the letter pay (80) is mem (40); half the numerical value of samech (60) is lamed (30) and half the numerical value of the letter chet (8) is dalet (4). When we combine the half value of each of these letters we have the word lamayd, learn! Another explanation: if we read the word pesach backwards it is an abbreviation for, chatzi samech potchin, One half of samech (that is, 30 days) we begin!