They will reverence my son. Strictly speaking, indeed, this thought does not apply to God; for He knew what would happen, and was not deceived by the expectation of a more agreeable result; but it is customary, [1] especially in parables, to ascribe to Him human feelings. And yet this was not added without reason; for Christ intended to represent, as in a mirror, how deplorable their impiety was, of which it was too certain a proof, that they rose in diabolical rage against the Son of God, who had come to bring them back to a sound mind. [2] As they had formerly, as far as lay in their power, driven God from his inheritance by the cruel murder of the prophets, so it was the crowning point of all their crimes to slay the Son, that they might reign, as in a house which wanted an heir. Certainly the chief reason why the priests raged against Christ was, that, they might not lose their tyranny, which might be said to be their prey; [3] for he it is by whom God chooses to govern, and to whom He has given all authority. The Evangelists differ also a little in the conclusion. For Matthew relates that he drew from them the confession, by which they condemned themselves; while Mark says simply that Christ declared what punishment must await servants so unprincipled and wicked. Luke differs, at first sight, more openly, by saying that they turned away with horror from the punishment which Christ had threatened. But if we examine the meaning more closely, there is no contradiction; for, in regard to the punishment which such servants deserved, there can be no doubt that they agreed with Christ, but when they perceived that both the crime and the punishment were made to apply to themselves, they deprecated that application.

Footnotes

1 - "C'est la coustume de l'Escriture;" -- "it is the custom of Scripture."

2 - "Qui estoit venu pour les retirer de leurs meschantes façons de faire;" -- "who had come to withdraw them from their wicked courses of life."

3 - "Pource qu'ils avoyent peur de perdre la proye; c'est a dire, de dimineur quelque chose de leur tyrannie;" -- "because they were afraid of losing the prey; that is to say, of diminishing something of their tyranny."

Last of all - Mark adds that this was an only son, greatly beloved.
This beautifully and most tenderly exhibits the love of God in sending his only Son, Jesus Christ, into the world to die for people. Long had he sent the prophets, and they had been persecuted and slain. There was no use in sending any more prophets to the people. They had done all that they could do. God had one only-begotten and well-beloved Son, whom he might send, and whom the world "ought" to reverence even as they should the Father, John 5:23. God is often represented in the Bible as giving his Son, his only-begotten and wellbeloved Son, for a lost world, John 3:16-17; 1-John 4:9, 1-John 4:14; Romans 8:3, Romans 8:32; Galatians 4:4.
Saying, They will reverence my son - To "reverence" means to honor, to esteem, to show deference to. It is that feeling which we have in the presence of one who is greatly our superior. It means to give to such a person, in our feelings and our deportment, the honor which is due to his rank and character.

Last of all he sent - his son - This requires no comment. Our Lord plainly means himself.
They will reverence - Εντραπησονται, they will reflect upon their conduct and blush for shame because of it, when they see my son. So the Syric and Persic.

But last of all,.... In the last times, in the last days, in the end of the world, the Jewish world, at the close of their ecclesiastic and civil state; after all the prophets had been sent, and finished their course, came the greatest prophet of all, to seal up the vision and prophecy:
he sent unto them son; not a servant as before, but a son; his own son, his only begotten son, the son of his love, his dearly beloved one; him he sent to these husbandmen the Jews. The Son of God, the Lord Jesus Christ, was sent only to the house of Israel: he was the minister of the circumcision; he was the great prophet raised up among them, and was sent to bless them, by turning them from their iniquities; he came to them, to his own, to them of his own nation, but they received him not:
saying, they will reverence my son. The Son of God is to be reverenced equally as his Father, since he is in nature and glory equal to him; and it is the will of his Father he should be so reverenced, as he is by the angels in heaven, and by the saints, both in heaven and in earth; but did these husbandmen reverence him? no; they despised and rejected him; they reproached and traduced him, as the vilest of men, and used him in the most cruel and barbarous manner. And did not his Father know this? yes; this is certain from his omniscience, which reaches to all future events, the most minute and contingent; and from the predictions of the usage of these persons of him, delivered long before it came to pass. Luke says, "it may be they will reverence him": so that it was not a positive affirmation, that they would do it, and which also is to be understood after the manner of men: that humanly speaking, it might be expected that they would give him reverence, in consideration of the dignity of his person, his character, and relation to God, which was his due and their duty; but he had a very different treatment from them.

But last of all he sent unto them his son, saying, They will reverence my son--In Mark (Mark 12:6) this is most touchingly expressed: "Having yet therefore one son, His well-beloved, He sent Him also last unto them, saying, They will reverence My Son." Luke's version of it too (Luke 20:13) is striking: "Then said the lord of the vineyard, What shall I do? I will send My beloved Son: it may be they will reverence Him when they see Him." Who does not see that our Lord here severs Himself, by the sharpest line of demarcation, from all merely human messengers, and claims for Himself Sonship in its loftiest sense? (Compare Hebrews 3:3-6). The expression, "It may be they will reverence My Son," is designed to teach the almost unimaginable guilt of not reverentially welcoming God's Son.

Last of all he sent unto them his son. This was the last and crowning effort of divine mercy; after which, on the one side, all the resources, even of heavenly love, are exhausted; on the other, the measure of sins is perfectly filled up.