Matthew 26:37

And he took with him Peter, and the two sons of Zebedee,
&c.] James and John, who perhaps were the strongest, and best able to bear the shocking sight, and were his favourite disciples; who were admitted to be with him at other times, when the rest were not; as at the raising of Jairus's daughter, ( Mark 5:37 ) , and moreover, these were at his transfiguration on the mount, ( Matthew 17:1 ) , which was a representation and presage of his glory; and so were very proper persons to be witnesses of his sorrows and agonies, which were the way to it; and three of them were taken by him for this purpose, being a sufficient number to bear testimony, since by the mouth of two or three witnesses everything is established:

and began to be sorrowful;
his soul was troubled on the same account six days before, ( John 12:27 ) , but was now sorrowful. He was a man of sorrows all his days, and acquainted with griefs, being reproached and persecuted by men: but now a new scene of sorrows opened; before he was afflicted by men, but now he is bruised, and put to grief by his Father: his sorrows now began, for they did not end here, but on the cross; not that this was but a bare beginning of his sorrows, or that these were but light in comparison of future ones; for they were very heavy, and indeed seem to be the heaviest of all, as appears from his own account of them; his vehement cry to his Father; his bloody sweat and agony; and the assistance he stood in need of from an angel; and the comfort and strength he received from him in his human nature: all which, put together, the like is not to be observed in any part of his sufferings:

and to be very heavy;
with the weight of the sins of his people, and the sense of divine wrath, with which he was so pressed and overwhelmed, that his spirits were almost quite gone; he was just ready to swoon away, sink and die; his heart failed him, and became like wax melted in the midst of his bowels, before the wrath of God, which was as a consuming fire: all which shows the truth, though weakness of his human nature, and the greatness of his sufferings in it. The human nature was still in union with the divine person of the Son of God, and was sustained by him, but left to its natural weakness, without sin, that it might suffer to the utmost, and as much as possible for the sins of God's elect.