I am thirsty. John 19:28
It is fitting that every word of Jesus on the cross should be looked at. Here we have the shortest of the seven cries.
Jesus is twice offered a drink whilst on the cross. He refuses the first as it has the customary sedative in, but the second he accepts. It is extend to Him on Hyssop branch. Why the hyssop? There are two places in the Old Testament that spring to mind that mention Hyssop. Psalm 51:7 where David prays to be cleansed with hysop, and then in the story of the Israelites at the first passover when they paint the lintel and the door posts withe blood of the lamb using hyssop. In simple terms it is the means which the blood of the sacrifice was transferred to the sinner and a symbol of cleansing.
In John’s gospel he is careful to mention that Jesus fulfilled the scripture, in particular he is referring to Psalm 69:21. This reminds me of the foundation of the word in our lives, that God will fulfil his promises, that what He says He will do.
But I think more than anything else, that Jesus thirsts speaks of his humanity.
It is an important point to recognise his humanity. For the recognition of the humanity of Jesus, that He came in the flesh, distinguishes between spirits that are not from God and false teachers. The acceptance of Jesus humanity is a big deal!
The New Testament is clear enough that Jesus has a human body. John 1:14 means at least this, and more: “The Word became flesh.” His humanity became one of the first tests of orthodoxy (1 John 4:2; 2 John 7). He was born (Luke 2:7). He grew (Luke 2:40, 52). He grew tired (John 4:6) and got thirsty (John 19:28) and hungry (Matthew 4:2). He became physically weak (Matthew 4:11; Luke 23:26). He died (Luke 23:46). And he had a real human body after his resurrection (Luke 24:39; John 20:20, 27).
Because of his humanity he can relate to us.
Since the children have flesh and blood, he too shared in their humanity so that by his death he might break the power of him who holds the power of death—that is, the devil— and free those who all their lives were held in slavery by their fear of death. For surely it is not angels he helps, but Abraham’s descendants. For this reason he had to be made like them,[k] fully human in every way, in order that he might become a merciful and faithful high priest in service to God, and that he might make atonement for the sins of the people. Because he himself suffered when he was tempted, he is able to help those who are being tempted. Hebrews 2:14-18
With out being human, he could not save us and could not identify with us. He is our substitute, our faithful high priest, the passover lamb, the one who makes atonement for us.