Mekhilta DeRabbi Yishmael
"ben ha'arbayim": I might think that this means at morning twilight.
Mekhilta DeRabbi Yishmael
It is, therefore, written (Devarim 16:6) "There shall you slaughter the Pesach in the evening." I might think that this is to be taken literally. It is, therefore, written (Ibid.) "at the time that you departed from Egypt." When was that? At midday, viz. (Exodus 12:41) "And it was in the middle of the day … that they left Egypt."
Mekhilta DeRabbi Yishmael
R. Shimon b. Yochai says: The verse comes to apply the first (activity) to the last (time mentioned in the verse) and the last, to the first, viz.: "the time of your departing," to its slaughtering; "at sundown," to its roasting; "in the evening," to its eating.