Exodus 12:6

12:6 You must care for it until the fourteenth day of this month, and then the whole community of Israel will kill it around sundown.

Numbers 9:3

9:3 In the fourteenth day of this month, at twilight, you are to observe it at its appointed time; you must keep it in accordance with all its statutes and all its customs.”

Deuteronomy 16:1-8

The Passover-Unleavened Bread Festival

16:1 Observe the month Abib and keep the Passover to the Lord your God, for in that month he brought you out of Egypt by night. 16:2 You must sacrifice the Passover animal (from the flock or the herd) to the Lord your God in the place where he chooses to locate his name. 16:3 You must not eat any yeast with it; for seven days you must eat bread made without yeast, symbolic of affliction, for you came out of Egypt hurriedly. You must do this so you will remember for the rest of your life the day you came out of the land of Egypt. 16:4 There must not be a scrap of yeast within your land for seven days, nor can any of the meat you sacrifice on the evening of the first day remain until the next morning. 16:5 You may not sacrifice the Passover in just any of your villages that the Lord your God is giving you, 16:6 but you must sacrifice it in the evening in the place where he chooses to locate his name, at sunset, the time of day you came out of Egypt. 16:7 You must cook and eat it in the place the Lord your God chooses; you may return the next morning to your tents. 16:8 You must eat bread made without yeast for six days. The seventh day you are to hold an assembly for the Lord your God; you must not do any work on that day.

Ezra 6:19

6:19 The exiles observed the Passover on the fourteenth day of the first month.

Ezekiel 45:21

45:21 “‘In the first month, on the fourteenth day of the month, you will celebrate the Passover, and for seven days bread made without yeast will be eaten.