Ex 12:17-18, Mk 14:12, Deut 16:3, 1 Cor 10:1-2, Col 2:12, Rom 6:3-4
God commanded the Israelites to keep the Feast of Unleavened Bread. (Ex 13:5-10, Ex 2:17-18)
Ex 13:5 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. 6 Seven days thou shalt eat unleavened bread, and in the seventh day shall be a feast to the Lord. 7 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. 8 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. 9 And it shall be for a sign unto thee upon thine hand, and for a memorial between thine eyes, that the Lord's law may be in thy mouth: for with a strong hand hath the Lord brought thee out of Egypt. 10 Thou shalt therefore keep this ordinance in his season from year to year.
Ex 2:17 And the shepherds came and drove them away: but Moses stood up and helped them, and watered their flock. 18 And when they came to Reuel their father, he said, How is it that ye are come so soon to day?
God made the people of Israel to keep the Feast of Unleavened Bread so that they would remember their exodus from Egypt for the rest of their lives. (Deut 16:3)
Deut 16:3 Thou shalt eat no leavened bread with it; seven days shalt thou eat unleavened bread therewith, even the bread of affliction; for thou camest forth out of the land of Egypt in haste: that thou mayest remember the day when thou camest forth out of the land of Egypt all the days of thy life.
The Feast of Unleavened Bread means baptism, which means that we died with Jesus and rose again. (1 Corinthians 10:1, Colossians 2:12, Romans 6:3-4)
1 Corinthians 10:1 Moreover, brethren, I would not that ye should be ignorant, how that all our fathers were under the cloud, and all passed through the sea;
Colossians 2:12 Buried with him in baptism, wherein also ye are risen with him through the faith of the operation of God, who hath raised him from the dead.
Romans 6:3 Know ye not, that so many of us as were baptized into Jesus Christ were baptized into his death? 4 Therefore we are buried with him by baptism into death: that like as Christ was raised up from the dead by the glory of the Father, even so we also should walk in newness of life.