Reference

Acts 20:18

And when they were come to him, he said unto them, Ye know, from the first day that I came into Asia, after what manner I have been with you at all seasons,
16

For Paul had determined to sail by Ephesus, because he would not spend the time in Asia: for he hasted, if it were possible for him, to be at Jerusalem the day of Pentecost.

17

And from Miletus he sent to Ephesus, and called the elders of the church.

18

And when they were come to him, he said unto them, Ye know, from the first day that I came into Asia, after what manner I have been with you at all seasons,

19

Serving the Lord with all humility of mind, and with many tears, and temptations, which befell me by the lying in wait of the Jews:

20

And how I kept back nothing that was profitable unto you, but have shewed you, and have taught you publickly, and from house to house,

Counter-Arguments

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

First Day of the Week

The verse explicitly states "from the first day that I came into Asia," referring to the beginning of Paul's time in Asia, not the "first day of the week." There is no mention of a weekly cycle or Sunday.