Why does the Torah need to give the date on which they left Egypt?
Knowing that the Molad (the birth of the New moon) that year occurred on Wednesday at midday, why does the Torah refer to the Thursday that they left Egypt as the fifteenth of Nisan and not the sixteenth?
Yeushalmi Rosh Hashanah, 2:5: Because, based on the Pasuk in Tehilim, 104 "Asah Yare'ach le'Mo'adim, Shemesh Yada Me'vo'o", Rosh Chodesh caanot fall in the middle of the day - only after sunset. 1
See Torah Temimah, note 2.
What are the connotations of "mi'Mochoras ha'Pesach"?
Rashi (in Re'ei Devarim, 16:1), Targum Onkelos and Targum Yonasan: It refers to the fifteenth of Nisan ? the day after they brought (Shechted 1 - R. Bachye [ate - Targum Yonasan]) 2 the Korban Pesach.
Why does the Torah write that they left Egypt the day after they Shechted the Korban Pesach, and not simply 'on the fifteenth of Nisan'?
Oznayim la'Torah: It was to answer the officers who informed Moshe that three days had passed and it was time to return to Egypt. The Torah therefore points out that they Shechted the Pesach in Egypt before they left, in which case the argument that they needed to go out into the desert to sacrifice to Hashem - in case the Egyptians would stone them - had fallen away. Consequently, when Par'oh sent them out, he must have sent them out for good. 1
Oznayim la'Torah: And "le'Einei Kol Mizrayim" refers tothe Pesach mentioned here as well.
How will we reconcile this Pasuk with the Pasuk in Re'ei Devarim, 16:1, which states that they went out at night?
Refer to Devarim, 16:1:5:1.