Albert Barnes Commentary Acts 28:25

"And when they agreed not among themselves, they departed after that Paul had spoken one word, Well spake the Holy Spirit through Isaiah the prophet unto your fathers," — Acts 28:25 (ASV)

Had spoken one word. This refers to one declaration of solemn prophecy, reminding them that it was the characteristic of the nation to reject the testimony of God, and that this was to be expected. It was the last solemn warning which we know Paul delivered to his countrymen, the Jews.

Well spake. Or, he spoke the truth; he justly described the character of the Jewish people. The passage quoted here was as applicable in the time of Paul as in that of Isaiah.

The Holy Ghost. That the Holy Spirit spoke by Isaiah is full proof of the inspiration of Isaiah.

By Esaias. That is, by Isaiah (Isaiah 6:9–10).