William Burkitt on John 19:28

Observe here, 1. The affliction or suffering which our Saviour complained of, and that is, thirst; there are two sorts of thirst, the one natural and proper, the other spiritual and figurative; Christ felt both at this time. His body thirsted by reason of those agonies which it laboured under. His soul thirsted in vehement desires, and fervent longings, to accomplish that great and difficult work he was now about.

2. The design and end of our Lord's complaint; that the scripture might be fulfilled, he said, I thirst. Our Savour finding that all was accomplished, which he was to do before his death, but only the fulfilling of that one scripture, They gave me vinegar to drink; Ps 69:21 he, for the accomplishment thereof, said, I thirst.

Whence note, that such were the agonies and extreme sufferings of our Lord Jesus Christ upon the cross, that they drank up his very spirits, and made him cry, I thirst.

2. That when Christ cried out, I thirst, it was to show, that whatever was foretold by the prophets concerning him, was exactly accomplished, and even to a circumstance fulfilled in him: That the scripture might be fulfilled, Jesus saith, I thirst.