When I was come again to Jerusalem - That is, three years after his conversion. See Galatians 1:17-18.
While I prayed in the temple - Paul, like other converts to Christianity from among the Jews, would naturally continue to offer his devotions in the temple. We meet with repeated instances of their continuing to comply with the customs of the Jewish people.
I was in a trance - Greek: ecstasy. See the notes on Acts 10:10. It is possible that he may here refer to what he elsewhere mentions 2 Corinthians 12:1-5 as “visions and revelations of the Lord.” In that place he mentions his being “caught up to the third heaven” 2 Corinthians 12:2 and “into paradise,” where he heard words which it was “not lawful (marg. possible) for a man to utter,” 2 Corinthians 12:4. It is not certain, however, that he alludes in this place to that remarkable occurrence. The narrative would rather imply that the Lord Jesus appeared to him in the temple in a remarkable manner, in a vision, and gave him a special command to go to the Gentiles. Paul had now stated the evidence of his conversion, which appears to have been satisfactory to them - at least they made no objection to his statement; he had shown, by his being in the temple, his respect for their institutions; and he now proceeds to show that in his other conduct he had been directed by the same high authority by which he had been called into the ministry, and that the command had been given to him in their own temple and in their own city.