"... The reference to this task of Elijah in Luke 1:17 seems to be a cocktail of elements from Malachi 3:24 and Sirach 48:10. As already noted by Raymond Brown, the Hebrew of these passages has a singular noun for heart and a plural noun for sons/children, while the Greek translation has two singular nouns. Luke has the same verb as the Greek version of Sirach 48:10 but has two plural nouns (fathers and children). Although clearly not a formal quotation, the explicit mention of Elijah and his spirit gives it the allure of a quite specific allusion. The next phrase recalls the mediating function of Elijah as mentioned in the other references to Elijah’s eschatological task. Instead of turning the heart of a man to his neighbor (as in LXX Malachi), John the Baptist will inspire the disobedient to follow the thoughts of the just. And while in Sirach 48:10 Elijah’s second task was to restore the twelve tribes of Israel, John the Baptist as an eschatological Elijah will work for the unity of the people: he will make ready a people prepared for the Lord (Luke 1:17). Whereas in Malachi 3:23 (LXX) and in Sirach 48:10 (LXX) the admonition is about the father-son relation, Luke 1:17 declares that John the Baptist will turn the hearts of the fathers to the (“children” = “boys and girls”). Like Malachi 3:23 (LXX) and Sirach 48:10, Luke 1:17 has no appeal addressed to the sons/children ..."