Midrash su Geremia 6:4

1) (Vayikra 23:5) ("In the first month, on the fourteenth day of the month, at twilight, it is Pesach to the L–rd.") I might think, when it gets dark; it is, therefore, written "day." If "day," I might think from the second hour (of the day); it is, therefore, written "at twilight." Just as twilight marks the "turning" of the day (towards evening), so, "day" (here) marks the turning of the day, from the sixth hour on. And even though there is no proof for this, it is intimated (in Yirmiyahu 6:4) "Woe unto us for the day is turning, for the shadows of evening have stretched forth."

"ben ha'arbayim": I might think that this means at morning twilight. 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." R. Nathan says: Whence is it derived that "ben ha'arbayim" signifies midday? Even though there is no proof for this, it is intimated in (Jeremiah 6:4) "Prepare for battle against her. Arise and let us go up at noon (midday). Woe unto us for the day is declining, for the shadows of evening go forth!" 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. Ben Betheira says (Exodus 12:6) "ben ha'arbayim" [lit., "between the evenings"]: Slaughter it between the two evenings, (the "evening" of the day [i.e., after midday] and the "evening" preceding the night).