Exodus 12:8

“And they shall eat the flesh in that night, roast with fire, etc.] The night of the fourteenth of Nisan; and as the Jews reckoned their days from the evening preceding, this must be the beginning of the fifteenth day, which being observed, will serve to reconcile some passages relating to this ordinance. The lamb was to be roasted, not only because its flesh thereby would be more palatable and savoury, but because soonest dressed that way, their present circumstances requiring haste; but chiefly to denote the sufferings of Christ, the antitype of it, when he endured the wrath of God, poured out as fire upon him; and also to show, that he is to be fed upon by faith, which works by love, or to…”

“roast with fire--for the sake of expedition; and this difference was always observed between the cooking of the paschal lamb and the other offerings (Ch2 35:13). unleavened bread--also for the sake of despatch (Deu 16:3), but as a kind of corruption (Luk 12:1) there seems to have been a typical meaning under it (Co1 5:8). bitter herbs--literally, "bitters"--to remind the Israelites of their affliction in Egypt, and morally of the trials to which God's people are subject on account of sin.”

“In that night - The night is thus clearly distinguished from the evening when the lamb was slain. It was slain before sunset, on the 14th, and eaten after sunset, the beginning of the 15th. With fire - Among various reasons given for this injunction the most probable and satisfactory seems to be the special sanctity attached to fire from the first institution of sacrifice (compare Genesis 4:4). And unleavened bread - On account of the hasty departure, allowing no time for the process of leavening: but the meaning discerned by Paul, 1 Corinthians 5:7-8, and recognized by the Church in all ages, was assuredly implied, though not expressly declared in the original institution. Compare our…”

“eat the: Mat 26:26; Joh 6:52-57 roast: Deu 16:7; Psa 22:14; Isa 53:10 unleavened: Exo 13:3, Exo 13:7, Exo 34:25; Num 9:11; Deu 16:3; Amo 4:5; Mat 16:12; Co1 5:6-8; Gal 5:9 with bitter: Exo 1:14; Num 9:11; Zac 12:10; Th1 1:6 Exodus 12:9”