The promise (hē epaggelia). The promise made by Jesus (Act 1:4) and foretold by Joel (Act 2:18).
To you (humin). You Jews. To your descendants, sons and daughters of Act 2:17.
To all that are afar off (pāsin tois eis makran. The horizon widens and includes the Gentiles. Those “afar off” from the Jews were the heathen (Isa 49:1; Isa 57:19; Eph 2:13, Eph 2:17). The rabbis so used it.
Shall call (an proskalesētai). First aorist middle subjunctive with an in an indefinite relative clause, a perfectly regular construction. The Lord God calls men of every nation anywhere whether Jews or Gentiles. It may be doubted how clearly Peter grasped the significance of these words for he will have trouble over this very matter on the housetop in Joppa and in Caesarea, but he will see before long the full sweep of the great truth that he here proclaims under the impulse of the Holy Spirit. It was a great moment that Peter here reaches.