Slaughtering at Twilight and Placing Blood on the Doorposts

"Between the evenings" (Exodus 12:6). I might hear it means at the fading of the sun; Scripture teaches "in the evening" (Deuteronomy 16:6). If "in the evening," I might think after dark; Scripture teaches "as the sun goes down" (Deuteronomy 16:6). If "as the sun goes down" -- "and you shall cook and eat" -- that is from after dark. Rabbi [Yehudah HaNasi] says: it says, "there you shall slaughter the Passover in the evening" (Deuteronomy 16:6); I might hear it as its plain sense; Scripture teaches "at the season of your going out from Egypt." When did Israel go out of Egypt? From the sixth hour and onward, as it says, "and it came to pass on the very day" (Exodus 12:41). Rabbi Natan says: from where do we know that "between the evenings" is from the sixth hour and onward? Though there is no proof for the matter, there is a remembrance of the matter: "for the day has turned, for the shadows of evening stretch out" (Jeremiah 6:4). Rabbi Shimon ben Yochai says: Scripture comes to equate the first with the last and the last with the first -- "the season of your going out" for its slaughter, "as the sun goes down" for its roasting, "in the evening" for its eating. "Between the evenings." Ben Beteira says: between the evenings, slaughter it -- give an evening for slaughtering and an evening for eating. "And they shall take from the blood" (Exodus 12:7). I might hear it whether by hand or with a vessel; Scripture teaches "which is in the basin (saf)" (Exodus 12:22). Scripture tells that a hollow was carved beside the threshold and they slaughter into it, for "saf" means nothing other than threshold, as it is written, "in their placing their threshold (sippam) by my threshold" (Ezekiel 43:8), and it is written, "and the posts of the thresholds (sippim) shook"; these are the words of Rabbi Yishmael. Rabbi Akiva says: "saf" means nothing other than a vessel, as it is said, "and the basins (sippot), and the snuffers, and the bowls" (1 Kings 7:50). "And they shall place it on the two doorposts" (Exodus 12:7): from the inside. Or perhaps only from the outside? Scripture teaches, "and I shall see the blood" (Exodus 12:13) -- what is seen by Me and not by others; these are the words of Rabbi Yishmael. Rabbi Yonatan says: from the inside. Or perhaps only from the outside? Scripture teaches, "and the blood shall be for you for a sign" (Exodus 12:13) -- for you for a sign and not for others for a sign. Rabbi Yitzchak says: always from the outside, so that the Egyptians would see and their innards be cut up with anguish. "And they shall place it on the two doorposts and on the lintel" (Exodus 12:7): I might hear that if one put this before that he has not fulfilled the duty; Scripture teaches, "and you shall touch the lintel and the two doorposts" (Exodus 12:22) -- thus if one put this before that, he has fulfilled it. We find ourselves learning that our ancestors in Egypt had three altars: the lintel and the two doorposts. Rabbi Shimon says: there were four -- the threshold, the lintel, and the two doorposts.