Acts 3:25

υἱοὶ τῶν προφητῶν. Render, sons of the prophets, i.e. of the same race as they, and hence what they spake is meant for you. For you is the prophet raised up whom Moses foretold.

καὶ τῆς διαθήκης, and [sons] of the covenant, i.e. heirs to its promises and obligations. So (2 Kings 14:14) hostages are called literally sons of the pledgings or compacts. LXX. οἱ νἱοὶ τῶν συμμίξεων. So the two anointed ones are called LXX. Zechariah 4:14 υἱοὶ τῆς πιότητος.

λέγων. The quotation is from Genesis 22:18, but the LXX. instead of πᾶσαι αἱ πατριαὶ has πάντα τὰ ἔθνη.