Having yet therefore one son, his well-beloved. There is strong evidence in favor of a different reading here: namely ( ἔτι ἕνα εἰχεν υἱὸν ἀγαπητὸν), he had yet one, a beloved son. There is something very touching in this form of expression.
Many messages had been sent; many means had been tried. But one other resource remained. "There is one, a beloved on. I will send him; they will, surely reverence him ( ἐντραπήσονται τὸν υἰόν μου).
They will reflect, and reflection will bring shame and submission and reverence." This was the last effort of Divine mercy—the sending of the Incarnate God, whom the Jews put to death without the city.
St. Mark's words seem rather to imply that they killed him within the vineyard, and cast out the dead body. But it is possible that in his narrative he mentions the climax first—they killed him, and then returns to a detail of the dreadful tragedy; they cast him out of the vineyard, and there slew him (See Matthew 21:39.