John 19:28

All things necessary for the fulfillment of Scripture that predicted the provision of redemption were almost accomplished (Gr. teleiothe). John was speaking proleptically again (cf. John 12:23; John 17:1; John 17:4); He spoke anticipating what would happen. Obviously Jesus still had to die. As the moment of His death drew nearer, Jesus expressed His thirst. This showed His true humanity. A man in Jesus’ physical condition would have also experienced torture by dehydration. It is paradoxical that the Water of Life should confess thirst (cf. John 4:4-14; John 7:38-39). The solution obviously is that Jesus had referred to Himself as the source of spiritual rather than physical water.

"One may no more assume that John’s emphasis on the cross as the exaltation of Jesus excludes his desolation of spirit than his emphasis on the deity of the Son excludes the Son’s true humanity." [Note: Beasley-Murray, p. 351.]

"By accepting the physical refreshment offered Him, the Lord once more indicated the completion of the work of His Passion. For, as He would not enter on it with His senses and physical consciousness lulled by narcotised [sic] wine, so He would not pass out of it with senses and physical consciousness dulled by the absolute failure of life-power. Hence He took what for the moment restored the physical balance, needful for thought and word. And so He immediately passed on to ’taste death for every man.’" [Note: Edersheim, 2:608-9.]

The Scripture that spoke of Messiah’s thirst may be Psalms 22:15 (cf. John 19:24) and or Psalms 69:21 (cf. John 2:17; John 15:25). Jesus’ mention of His thirst resulted in the soldier callously giving Him vinegar to drink, which Psalms 69:21 mentioned. Thus John stressed that Jesus’ death not only fulfilled God’s will but also prophetic Scripture.