Exodus 12:8

Roast with fire. The meat of sacrificial meals was commonly boiled (1 Sam. 2:14, 15), but for the paschal lamb specific directions were given not to eat it raw or boil it, but to roast it (see Ex. 12:9). The reasons may have been that roasting was easier than boiling and that it would have been difficult to boil the “lamb” without cutting it into pieces, a procedure that seems also to have been prohibited (see Ex. 12:46; Num. 9:12; John 19:36).

Unleavened bread. The roasted lamb was to be eaten with unleavened bread, for leaven produces fermentation, a natural symbol of impurity and moral corruption. For this reason leaven was also excluded from cereal sacrifices as defiling (Lev. 2:11). That Paul understood leaven in this sense is seen from his interpretation of the Passover as a type of Christ (1 Cor. 5:7, 8).

With bitter herbs. That “bitter herbs” is the correct translation of a Hebrew word meaning literally “bitter [things]” cannot reasonably be doubted. Though it is not known what kind of “herbs” were used in Egypt, Palestinian Jews later used two varieties of lettuce, a kind of thistle, endive, and cress. Lettuce and endive are native to Egypt and Palestine. The latter may be found from the beginning of the winter months to the end of March, and lettuce in April and May. This probably accounts for the fact that the Jews considered these plants necessary ingredients of the Passover meal. Whatever bitter herbs were used, it is obvious that they were designed to remind the participants of their bondage and bitter suffering in the land of Egypt.