Acts 22:17

And it came to pass, that, when I had returned to Jerusalem, and while I prayed in the temple, I fell into a trance, and saw him saying unto me, Make haste, and get thee quickly out of Jerusalem; because they will not receive of thee testimony concerning me. And I said, Lord, they themselves know that I imprisoned and beat in every synagogue them that believed on thee: and when the blood of Stephen thy witness was shed, I also was standing by, and consenting, and keeping the garments of them that slew him. And he said unto me, Depart: for I will send thee forth far hence unto the Gentiles.

Harrison's brief analysis of this is correct:

Here Paul tells that he had left Jerusalem in response to a word from the Lord. While he was praying in the temple as a faithful Jew, God had warned him in a trance that Jerusalem would not receive his message and that therefore he should get quickly out of Jerusalem. Paul protested (even to the Lord) that the Jews' knowledge of his earlier zeal and sincerity in persecuting the Christians would convince them of the reality of his conversion. The Lord replied that he should leave Jerusalem, for he would be sent far away unto the Gentles (RSV).[21]

In the light of this, there must remain a question of whether or not Paul was completely obedient to the Lord when, contrary to advice of many friends, he nevertheless insisted on going there.

Paul's mention of the temple here, and his praying there, even having the vision there, - all this shows that, at the time, Paul did not understand that the temple itself had been designated by Jesus as "The House Desolate," that it was truly a den of thieves and robbers, that the glory of it was of the past tense only, that its day of grace was even at that very time expiring, and that the last word from God that was ever uttered there was this command for Paul to get quickly out of the place. However, Paul's love of his Jewish brethren was such that he even dared, in a sense, to go against the word of the Lord in an effort to reach them. Before his dealings with the temple Jews were over, however, it may be assumed that Paul got the message fully.

In the light of the above, it is likewise clear that the custom of the earliest Christians of going regularly to the temple for prayer was not something God desired that they should do, but rather something which he allowed, as being founded in their natural inclinations, a habit they could not quickly shake off.

The Gentiles ... With this word from Paul, the riot broke out again. It was as evil and unreasonable as all riots; and only the protection of the soldiers prevented their murder of the apostle on the spot.