Deuteronomy 16:3

Ver. 3. Even the bread of affliction— So called because it was insipid, and not easily digested, and therefore served to remind them of their afflicted state in Egypt. Concerning these several feasts, we refer to the passages in the Margins of our Bibles. The word passover, in ver. 2 signifies not only the paschal lamb, which was offered on the fourteenth day, but all the paschal service which followed after as appears by the next words, of the flock and the herd.