Deuteronomy 16:3

“Thou shalt eat no leavened bread with it, etc.] With the passover, as the Targum of Jonathan expresses it; that is, with the passover lamb, nor indeed with any of the passover, or peace offerings, as follows; (see <021208> Exodus 12:8) seven days shall ye eat unleavened bread therewith; with the passover; this plainly shows, that by the passover in the preceding verse is not meant strictly the passover lamb, for that was eaten at once on the night of the fourteenth of the month, and not seven days running, and therefore must be put for the whole solemnity of the feast, and all the sacrifices of it, both the lamb of the fourteenth, and the Chagigah of the fifteenth, and every of the peace…”

“seven days shalt thou eat unleavened bread--a sour, unpleasant, unwholesome kind of bread, designed to be a memorial of their Egyptian misery and of the haste with which they departed, not allowing time for their morning dough to ferment.”

“The cardinal point on which the whole of the prescriptions in this chapter turn, is evidently the same as has been so often insisted on in the previous chapters, namely, the concentration of the religious services of the people round one common sanctuary. The prohibition against observing the great Feasts of Passover, Pentecost, and tabernacle, the three annual epochs in the sacred year of the Jew, at home and in private, is reiterated in a variety of words no less than six times in the first sixteen verses of this chapter Deuteronomy 16:2, Deuteronomy 16:6-7, Deuteronomy 16:11, Deuteronomy 16:15-16. Hence, it is easy to see why nothing is here said of the other holy days. The Feast of…”

“With it - Or, in it, that is, during the time of the feast of the passover. Bread of affliction - Bread which is not usual nor pleasant, to put thee in mind both of thy miseries endured in Egypt; and of thy hasty coming out of it, which allowed thee no time to leaven or prepare thy bread. Deuteronomy 16:4”

“16:3 Although yeast frequently symbolizes corruption (Lev 6:14-17; Matt 16:11-12), it was avoided at the original Passover because the Israelites had no time to wait for yeast bread to rise (see Exod 12:10-14). The elements of the yearly Passover celebration reminded the Israelites of what God had done for them.”

“eat no: Exo 12:15, Exo 12:19, Exo 12:20, Exo 12:39, Exo 13:3-7, Exo 34:18; Lev 23:6; Num 9:11, Num 28:17; Co1 5:8 the bread: Kg1 22:27; Psa 102:9, Psa 127:2; Zac 12:10; Co2 7:10, Co2 7:11; Th1 1:6 for thou camest: Exo 12:32, Exo 12:33, Exo 12:39 mayest: Exo 12:14, Exo 12:26, Exo 12:27, Exo 13:7-9; Psa 111:4; Luk 22:19; Co1 11:24-26 Deuteronomy 16:4”