Exodus 13:10

Therefore, you shall keep this ordinance at this time from year to year.

Exodus 12:14

‘Now this day will be a memorial to you, and you shall keep it as a feast to the Lord; throughout your generations you are to celebrate it as an ordinance forever.

Exodus 12:24-25

You shall observe this event [concerning Passover] as an ordinance for you and for your children forever.

Exodus 23:15

You shall observe the Feast of Unleavened Bread; for seven days you shall eat unleavened bread, as I commanded you, at the appointed time in the month of Abib, for in it you came out of Egypt. No one shall appear before Me empty-handed [but you shall bring sacrificial offerings].

Leviticus 23:6

The Feast of Unleavened Bread to the Lord is on the fifteenth day of the same month; for seven days you shall eat unleavened bread.

Deuteronomy 16:3-4

You shall not eat leavened bread with it; instead, for seven days you shall eat the Passover with unleavened bread, the bread of affliction (for you left the land of Egypt in haste); [do this] so that all the days of your life you may remember [thoughtfully] the day when you came out of the land of Egypt.

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
‘Now this day will be a memorial to you, and you shall keep it as a feast to the Lord; throughout your generations you are to celebrate it as an ordinance forever.
Exodus 23:15
You shall observe the Feast of Unleavened Bread; for seven days you shall eat unleavened bread, as I commanded you, at the appointed time in the month of Abib, for in it you came out of Egypt. No one shall appear before Me empty-handed [but you shall bring sacrificial offerings].
Leviticus 23:6
The Feast of Unleavened Bread to the Lord is on the fifteenth day of the same month; for seven days you shall eat unleavened bread.
Deuteronomy 16:3
You shall not eat leavened bread with it; instead, for seven days you shall eat the Passover with unleavened bread, the bread of affliction (for you left the land of Egypt in haste); [do this] so that all the days of your life you may remember [thoughtfully] the day when you came out of the land of Egypt.