What therefore will the lord of the vineyard do? In St. Matthew's narrative the scribes answer this question. St. Luke, as St. Mark here, assigns the answer to our Lord. It would seem probable that the scribes first answered him, and that then he himself repeated their answer, and confirmed it by his looks and gesture; so that from thence, as well as from what followed, they might sufficiently understand that he spake these things of them. Then, according to St. Luke (Luke 20:16), they subjoined the words, "God forbid!" an expression wrung from their consciences, which accused them and told them that the parable applied to them. Here, then, we have a distinct prediction of the rejection of the Jews and the call of the Gentiles.
This quotation is from Psalms 118:22, where David prophesies of Christ. The meaning is plainly this, that the chief priests and scribes, as the builders of the Jewish Church, rejected Christ from the building as a useless stone; yea, more—they condemned and crucified him. They rejected him ( ἀπεδοκίμασαν). The verb in the Greek implies that the stone was first examined and then deliberately refused. But this stone, thus disallowed and set at nought by the builders, was made the head of the corner. The image here is different from that used in the Epistles, where Christ is spoken of as the chief Corner-stone in the foundation. Here he is represented as the Corner-stone in the cornice. In real truth he is both. He is the tried Foundation-stone. But he is also the Head of the corner. In the great spiritual building he is "all and in all," uniting and binding together all in one. This was the Lord's doing ( παρὰ κυρίου ἐγένετο αὕτη); literally, this was from the Lord. The feminine ( αὔτη) refers apparently to κεφαλή. This lifting up of the despised and rejected stone to be the Corner-stone of the cornice was God's work; and was a fitting object for wonder and praise.