Augustine of Hippo

They had remarked upon Him already, as being over lenient. Of Him indeed it had been prophesied, Ride on because of the word of truth, of meekness, and of righteousness. (Ps. 44) So as a teacher He exhibited truth, as a deliverer meekness, as a judge righteousness. When He spoke, His truth was acknowledged; when against His enemies He used no violence, His meekness was praised. So they raised the scandal on the score of justice. …

Catena Aurea by Aquinas ↗

Jerome

The Scribes and Pharisees kept accusing her and kept earnestly pressing the case, for they wished to stone her to death, according to the law. "But Jesus, stooping down, began to write with his finger on the ground," the sins, to be sure, of those who were making the accusation, as well as the sins of all mortal beings according to what is written in the prophet, "Those who depart from you shall be written in the earth."

Against the Pelagians 2.17 ↗

Bede

When the Lord was about to give pardon to the sinful woman, he desired to write with his finger on the ground, in order to point out that it was he himself who once wrote the Ten Commandments of the law on stone with his finger, that is, by the action of the Holy Spirit. And it is good that the law was written upon stone, since it was given to subdue the inmost hearts of a hard-hearted and defiant people.

Homilies on the Gospels 1.25 ↗