Theophylact of Ohrid

Three times did Pilate acquit Christ, for it follows, And he said unto them the third time, Why, what evil hath he done? I will chastise him, and let him go.

Catena Aurea by Aquinas ↗

Bede

But he said to them the third time: "What evil has this man done? I find no cause of death in him. I will chastise him, therefore, and release him." He earnestly sought to satisfy the people with this chastisement, to prevent them from raging to the extent of crucifying the Savior, not only having offered him by pleading but even mocking and scourging, showing it to the desires of the wicked, and the words of the evangelist John, and even the column to which he is bound bears witness. …

On the Gospel of Luke ↗

Bonaventure

Fourth, as regards the repugnance between the condemnation and right reason, there is subjoined: But he said to them a third time: What evil has this man done? I find no cause of death in him. For since there was no cause of death in him, to kill him was against the dictate of right reason. — And because for the envious mind reason does not suffice without punishment, he therefore adds: I will therefore chastise him and release him. …

Commentary on Luke, Chapter 23 ↗