Reference

Leviticus 23:5

In the fourteenth day of the first month at even is the Lord’s passover.
3

Six days shall work be done: but the seventh day is the sabbath of rest, an holy convocation; ye shall do no work therein: it is the sabbath of the Lord in all your dwellings.

4

These are the feasts of the Lord, even holy convocations, which ye shall proclaim in their seasons.

5

In the fourteenth day of the first month at even is the Lord’s passover.

6

And on the fifteenth day of the same month is the feast of unleavened bread unto the Lord: seven days ye must eat unleavened bread.

7

In the first day ye shall have an holy convocation: ye shall do no servile work therein.

Counter-Arguments

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

First Day of the Week

The verse specifies "the fourteenth day of the first month" and "at even," which are specific temporal markers, but it makes no mention of "the first day of the week" or any equivalent phrasing.