If Luke 1:17 was quoting the LXX version of Malachi 4:6, Why was ἐπιστρέφω used for “to turn” instead of copying ἀποκαθίστημι?

Question

Should historians think Luke’s author used an available copy of LXX to reference Malachi 4:6, if the LXX-Malachi uses the Greek word “ἀποκαθίστημι” instead of “ἐπιστρέφω” in Luke 1:17?

[LXX Malachi 4:6] ὃς ἀποκαταστήσει καρδίαν πατρὸς πρὸς υἱὸν καὶ καρδίαν ἀνθρώπου πρὸς τὸν πλησίον αὐτοῦ μὴ ἔλθω καὶ πατάξω τὴν γῆν ἄρδην

[LXX Luke 1:17] καὶ αὐτὸς προελεύσεται ἐνώπιον αὐτοῦ ἐν πνεύματι καὶ δυνάμει Ἠλίου ἐπιστρέψαι καρδίας πατέρων ἐπὶ τέκνα καὶ ἀπειθεῖς ἐν φρονήσει δικαίων ἑτοιμάσαι κυρίῳ λαὸν κατεσκευασμένον

Why did the Author of LXX-Luke not directly quote from his copy of LXX-Malachi, if Luke 1:17 was directly referencing Malachi 4:6?

Answer 1

The text of Luke 1:17 is:

καὶ αὐτὸς προελεύσεται ἐνώπιον αὐτοῦ ἐν πνεύματι καὶ δυνάμει Ἡλεία, ἐπιστρέψαι καρδίας πατέρων ἐπὶ τέκνα καὶ ἀπειθεῖς ἐν φρονήσει δικαίων, ἑτοιμάσαι Κυρίῳ λαὸν κατεσκευασμένον. = And he will go on before the Lord in the spirit and power of Elijah, to turn the hearts of the fathers to their children and the disobedient to the wisdom of the righteous—to make ready a people prepared for the Lord.”

The text of Mal 4:4, 5 (LXX) is:

καὶ ἰδοὺ ἐγὼ ἀποστελῶ ὑμῖν ᾿Ηλίαν τὸν Θεσβίτην, πρὶν ἢ ἐλθεῖν τὴν ἡμέραν Κυρίου τὴν μεγάλην καὶ ἐπιφανῆ, ὃς ἀποκαταστήσει καρδίαν πατρὸς πρὸς υἱὸν καὶ καρδίαν ἀνθρώπου πρὸς τὸν πλησίον αὐτοῦ, μὴ ἐλθὼν πατάξω τὴν γῆν ἄρδην = And, behold, I will send to you Elias the Thesbite, before the great and glorious day of the Lord comes; 5 who shall turn again the heart of the father to the son, and the heart of a man to his neighbour, lest I come and smite the earth grievously

Observe that the text of Luke 1:17 is only vaguely similar to the LXX and does not really follow it at all. The Hebrew of Mal 4:5, 6 is

Behold, I will send you Elijah the prophet before the coming of the great and awesome Day of the LORD. And he will turn the hearts of the fathers to their children, and the hearts of the children to their fathers. Otherwise, I will come and strike the land with a curse.”

Neither is the text of Luke 1:17 all that similar to the Hebrew. Indeed, Luke appears to to paraphrase both.