Reference

Exodus 34:18

The feast of unleavened bread shalt thou keep. Seven days thou shalt eat unleavened bread, as I commanded thee, in the time of the month Abib: for in the month Abib thou camest out from Egypt.
16

And thou take of their daughters unto thy sons, and their daughters go a whoring after their gods, and make thy sons go a whoring after their gods.

17

Thou shalt make thee no molten gods.

18

The feast of unleavened bread shalt thou keep. Seven days thou shalt eat unleavened bread, as I commanded thee, in the time of the month Abib: for in the month Abib thou camest out from Egypt.

19

All that openeth the matrix is mine; and every firstling among thy cattle, whether ox or sheep, that is male.

20

But the firstling of an ass thou shalt redeem with a lamb: and if thou redeem him not, then shalt thou break his neck. All the firstborn of thy sons thou shalt redeem. And none shall appear before me empty.

Counter-Arguments

The strongest case that this verse does not belong in this theme.

First Day of the Week

The verse explicitly mentions "seven days" and "the month Abib" in relation to the Feast of Unleavened Bread, but it makes no mention of a "first day of the week" or any weekly cycle.

Time-Bound Fulfillment

This verse describes a recurring annual observance with a fixed duration, not a prophecy given with a defined duration that is expected to be recognized when fulfilled. The "time of the month Abib" refers to a past event (coming out of Egypt) and a present command for an annual feast, not a future prediction.