Acts 22:17

And it came to pass, that when I was come again to
Jerusalem
Which was three years after his conversion; for he did not immediately return to Jerusalem, but went into Arabia; and when he returned to Damascus, which was three years after he came to Jerusalem; see ( Galatians 1:17 Galatians 1:18 )

even while I prayed in the temple;
the temple was an house of prayer; hither persons resorted for that purpose; and as the apostle had been used to it, he continued this custom, and during the time of prayer he fell into an ecstasy:

I was in a trance:
and knew not whether he was in the body, or out of the body: whether this was the time he refers to in ( 2 Corinthians 12:2 ) is not certain, though probable.