Albert Barnes Commentary Acts 24:21

"except it be for this one voice, that I cried standing among them, Touching the resurrection of the dead I am called in question before you this day." — Acts 24:21 (ASV)

Except it be for this one voice—that is, for this one expression or declaration. This was what Paul had said before the council—the main thing on which he had insisted; and he calls on them to testify to this and to show, if they could, that in this declaration he had been wrong.

Chubb and other infidels have supposed that Paul here acknowledges that he was wrong in the declaration he made when he said that he was called in question for the doctrine of the resurrection of the dead (Acts 23:6). They suggest his conscience reproached him for appearing to be time-serving, for concealing the true cause of offense against him, and for attempting to take advantage of their divisions of sentiment and endeavoring to produce discord in the council.

But against this interpretation, we may urge the following considerations:

1. Paul wished to fix their attention on the main thing which he had said before the council.
2. It was true, as has been shown on the passage (Acts 23:1–10), that this was the principal doctrine which Paul had been defending.
3. If they were prepared to witness against him for holding and teaching the resurrection of the dead as a false or evil doctrine, he called on them to do it. Since this had been the only thing they had witnessed before the council, he calls on them to testify only to what they knew and to show, if they could, that this was wrong.

Touching the resurrection, etc. Respecting the resurrection (Acts 23:6).