"The Israelites are to observe the Passover at its appointed time.

Exodus 12:6
You must keep it until the fourteenth day of the month, when the whole assembly of the congregation of Israel will slaughter the animals at twilight.

Leviticus 23:5
The Passover to the LORD begins at twilight on the fourteenth day of the first month.

Numbers 9:3
You are to observe it at the appointed time, at twilight on the fourteenth day of this month, in accordance with its statutes and ordinances."

Deuteronomy 16:1
Observe the month of Abib and celebrate the Passover to the LORD your God, because in the month of Abib the LORD your God brought you out of Egypt by night.

Deuteronomy 16:2
You are to offer to the LORD your God the Passover sacrifice from the herd or flock in the place the LORD will choose as a dwelling for His Name.

2 Kings 23:21
The king commanded all the people, "Keep the Passover of the LORD your God, as it is written in this Book of the Covenant."

Let the children of Israel also keep the passover at his appointed season.