It is more likely that the Apostle now joined into one speech both what the Lord directly said to him and what Ananias said to him. He expressed this in a free presentation, without keeping to the letter.
For the words spoken to him by Ananias were also words of the Lord Himself to Ananias, and through him to Paul. The Apostle spoke this address before a king and a secular society.
It was inconvenient for him to enter into details. He might fear that highly placed persons would not continue listening to him. Yet it was necessary for him to speak of his mission to the Gentiles.
Therefore he placed in one presentation what the Lord said to him directly at His appearance, and indirectly through Ananias. There is no real inaccuracy here.
Both sets of words are words of the Lord Himself. Meanwhile, to place them together in one presentation was both more convenient and more advantageous for the Apostle in his present position.
As for the features of this speech that are not found even in Ananias’s words to Paul, in verses 17 and 18, one may suppose that chapters 9 and 22 do not transmit all of Ananias’s speech to Paul.
This often happens in the transmission of speeches, not only of the apostles, but also of the Lord Himself. The essence of the speech is transmitted.
There can be no doubt that Ananias and Paul, after the extraordinary event of the conversion, spoke much with one another. This is very natural in their position.
The sacred historian and the Apostle himself transmit the essence of these speeches with certain very natural nuances. Thus this important feature of the Apostle’s present speech is easily explained.
It is a feature arising from his very position at that time. “But rise and stand on your feet,” and so forth. Encouraging Saul, the Lord reveals to him the purpose of His appearance to him.
It is to make him a minister and witness, on a level with the other apostles (Acts 1:8), yet chiefly for the conversion of the Gentiles (verse 18). In carrying out this mission, the Lord’s protection is promised to him in dangers.
“To appoint” means, properly, to predestine. It is the same expression used for the predestination of the Messiah to come to the Hebrew people, and for the future judgment. Compare Acts 3:20 and the note.
“What you have seen and what I will reveal to you.” At the Lord’s appearance to him, Paul saw Him risen and glorified. He must be a witness of His Resurrection, as were the other apostles.
See Acts 3:15; 1 Cor 9:1; 1 Cor 15:4-8. Witness to the risen Lord must be the foundation of Paul’s preaching about Christ, as it also serves as the foundation of the preaching of the other apostles.
The final expression, “what I will reveal to you,” must be understood according to the Greek construction. The Lord Himself promises to appear to the newly called witness and reveal His will to him.
This we do in fact see in his history. See Acts 22:17 and following, Acts 23:11, and other passages.