Charles Ellicott Commentary Acts 13:31

"and he was seen for many days of them that came up with him from Galilee to Jerusalem, who are now his witnesses unto the people." — Acts 13:31 (ASV)

And he was seen many days.—The language is that of one who had conversed with the witnesses, and had convinced himself of the truth of their testimony. We find what the Apostle had in his thoughts in a more expanded form in 1 Corinthians 15:3–8.

Who are his witnesses.—More accurately, who are now his witnesses.

Unto the people.—The word is used in its distinctive sense as applied to those who were the people of God. (Acts 26:23.)