Exodus 13:6
“Seven days thou shalt eat unleavened bread, and in the seventh day shall be a feast to the Lord.”
This day came ye out in the month Abib.
And it shall be when the Lord shall bring thee into the land of the Canaanites, and the Hittites, and the Amorites, and the Hivites, and the Jebusites, which he sware unto thy fathers to give thee, a land flowing with milk and honey, that thou shalt keep this service in this month.
Seven days thou shalt eat unleavened bread, and in the seventh day shall be a feast to the Lord.
Unleavened bread shall be eaten seven days; and there shall no leavened bread be seen with thee, neither shall there be leaven seen with thee in all thy quarters.
And thou shalt shew thy son in that day, saying, This is done because of that which the Lord did unto me when I came forth out of Egypt.
Counter-Arguments
The strongest case that this verse does not belong in this theme.

Cross-References
“Purge out therefore the old leaven, that ye may be a new lump, as ye are unleavened. For even Christ our passover is sacrificed for us:”
“And kept the feast of unleavened bread seven days with joy: for the Lord had made them joyful, and turned the heart of the king of Assyria unto them, to strengthen their hands in the work of the house of God, the God of Israel.”
“But ye shall offer an offering made by fire unto the Lord seven days: in the seventh day is an holy convocation: ye shall do no servile work therein.”
“The feast of unleavened bread shalt thou keep. Seven days thou shalt eat unleavened bread, as I commanded thee, in the time of the month Abib: for in the month Abib thou camest out from Egypt.”
“Seven days shall ye eat unleavened bread; even the first day ye shall put away leaven out of your houses: for whosoever eateth leavened bread from the first day until the seventh day, that soul shall be cut off from Israel.”