Exodus 13:10

So let this order be kept, at the right time, from year to year.

Exodus 12:14

And this day is to be kept in your memories: you are to keep it as a feast to the Lord through all your generations, as an order for ever.

Exodus 12:24-25

And you are to keep this as an order to you and to your sons for ever.

Exodus 23:15

You are to keep the feast of unleavened bread; for seven days let your bread be without leaven, as I gave you orders, at the regular time in the month Abib (for in it you came out of Egypt); and let no one come before me without an offering:

Leviticus 23:6

And on the fifteenth day of the same month is the feast of unleavened bread; for seven days let your food be unleavened bread.

Deuteronomy 16:3-4

Take no leavened bread with it; for seven days let your food be unleavened bread, that is, the bread of sorrow; for you came out of the land of Egypt quickly: so the memory of that day, when you came out of the land of Egypt, will be with you all your life.

Treasury of Scripture Knowledge

Summary

Thou shalt therefore keep this ordinance in his season from year to year.

Bible References

General references

Exodus 12:14
And this day is to be kept in your memories: you are to keep it as a feast to the Lord through all your generations, as an order for ever.
Exodus 23:15
You are to keep the feast of unleavened bread; for seven days let your bread be without leaven, as I gave you orders, at the regular time in the month Abib (for in it you came out of Egypt); and let no one come before me without an offering:
Leviticus 23:6
And on the fifteenth day of the same month is the feast of unleavened bread; for seven days let your food be unleavened bread.
Deuteronomy 16:3
Take no leavened bread with it; for seven days let your food be unleavened bread, that is, the bread of sorrow; for you came out of the land of Egypt quickly: so the memory of that day, when you came out of the land of Egypt, will be with you all your life.

Basic English, produced by Mr C. K. Ogden of the Orthological Institute - public domain