A.T. Robertson Commentary Acts 13:33

"that God hath fulfilled the same unto our children, in that he raised up Jesus; as also it is written in the second psalm, Thou art my Son, this day have I begotten thee." — Acts 13:33 (ASV)

Hath fulfilled (εκπεπληρωκεν). Hath filled out (εκ).

Unto our children (τοις τεκνοις ημων). The MSS. vary greatly here about ημων (our), some have αυτων, some αυτων ημιν. Westcott and Hort consider these readings "a primitive error" for ημιν (to us) taken with αναστησας Ιησουν (having for us raised up Jesus). This raising up (from ανιστημ, set up) as in 3:22; 7:37 refers not to resurrection (verse 34), but to the sending of Jesus (two raisings up).

In the second psalm (εν τω ψαλμω τω δευτερω). Psalms 2:7. D has πρωτω because the first psalm was often counted as merely introductory.