Exodus 12:34

12:34 So the people took their dough before the yeast was added, with their kneading troughs bound up in their clothing on their shoulders.

Exodus 12:39

12:39 They baked cakes of bread without yeast using the dough they had brought from Egypt, for it was made without yeast – because they were thrust out of Egypt and were not able to delay, they could not prepare food for themselves either.