Exodus 12:15 gives the same command: eat unleavened bread for seven days and remove leaven — reinforcing the instruction in v20.

Exodus 34:25 also forbids leaven with the Passover sacrifice — connecting the feast to offering regulations.

Deuteronomy 16:3 repeats the command and adds the historical reason: bread of affliction remembering the haste of the Exodus.

Leviticus 2:11 also forbids leaven — in grain offerings — broadening the unleavened bread requirement beyond the feast.