Make thee a minister. See on Acts 9:10, 15, where God instructs Paul through His representative, Ananias of Damascus.
Which thou hast seen. Textual evidence is divided (cf. p. 10) between this and the reading “in which you have seen me.” Paul actually saw his Lord (Acts 22:17, 18; 1 Cor. 9:1; 15:8). It was on the basis of this direct commission that Paul laid his claim to apostleship. He knew by personal experience that Christ was risen indeed (cf. Gal. 1:15—18; 1 Tim. 2:7). To be genuine, a witness must have firsthand knowledge of that concerning which he testifies.
I will appear. Christ appeared to Paul upon repeated occasions, to guide and to intervene (see Acts 18:9, 10; 22:17-21; 23:11; 1 Cor. 11:23; 2 Cor. 12:1-5). Paul was an eyewitness of the risen Lord, and knew from personal experience the truth of the resurrection.