28 Afterwards, Jesus knowing that all things were now accomplished, that the scripture might be fulfilled, said: I thirst. 29 Now there was a vessel set there full of vinegar. And they, putting a sponge full of vinegar and hyssop, put it to his mouth. 30 Jesus therefore, when he had taken the vinegar, said: It is consummated. And bowing his head, he gave up the ghost.
Augustine: Jesus knowing that all things were now accomplished; i.e. knowing the prophecy in the Psalms, And when I was thirsty, they gave me vinegar to drink [Ps 69:21], said, I thirst.
The hyssop around which they put the sponge full of vinegar, being a mean herb, taken to purge the breast, represents the humility of Christ, which they hemmed in and thought they had circumvented. For we are made clean by Christ s humility.
Bede: It may be asked here, why it is said, When Jesus had received the vinegar, when another Evangelist says, He would not drink [Matt 27:34]. But this is easily settled. He did not receive the vinegar, to drink it, but fulfill the prophecy.
Chrysostom: He did not bow His head because He gave up the ghost, but He gave up the ghost because at that moment He bowed His head. Whereby the Evangelist intimates that He was Lord of all.
Augustine: Who ever had such power to sleep when he wished, as our Lord had to die when He wished? What power must He have, for our good or evil, Who had such power dying?
Theophylact: Our Lord gave up His ghost to God the Father, showing that the souls of the saints do not remain in the tomb, but go into the hand of the Father of all while sinners are reserved for the place of punishment, i.e. hell.
Scripture from the Douay-Rheims Bible. Commentary from St. Thomas Aquinas, Catena Aurea, Vol. IV (London: Rivington, 1845).