Theophylact of Ohrid

Matthew says that the scribe approached (Christ) "testing" (Matt. 22:35), while Mark notes of him that he "answered wisely." Do the evangelists contradict each other? No; at first he probably asked as one testing, but then he was enlightened by Christ's answer and responded wisely, and thus was praised. However, note that even the praise testifies of him as still imperfect, for Christ did not say: you are in the Kingdom of God itself, but only "not far." Why then does the lawyer so boldly put his question to Christ? …

Commentary on Mark ↗

Augustine of Hippo

Nor let it trouble us that Matthew says, that he who addressed this question to the Lord tempted Him; for it may be that though he came as a tempter, yet he was corrected by the answer of the Lord. Or at all events, we must not look upon the temptation as evil, and done with the intention of deceiving an enemy, but rather as the caution of a man who wished to try a thing unknown to him.

Catena Aurea by Aquinas ↗

Bede

And one of the scribes came up who had heard them disputing. And seeing that he had answered them well, he asked him which commandment was the first of all. Jesus answered him that the first of all commandments is: Hear, O Israel, the Lord your God is one God. And you shall love the Lord your God with all your heart, and with all your soul, and with all your mind, and with all your strength. This is the first commandment. The second is like it: You shall love your neighbor as yourself. …

On the Gospel of Mark ↗

Glossa Ordinaria

After that the Lord confuted the Pharisees, and the Sadducees, who tempted Him, it is here shown how He satisfied the Scribe who questioned Him; wherefore it is said, And one of the scribes came, and having heard them reasoning together, and perceiving that he had answered them well, asked him, Which is the first commandment of all?

Catena Aurea by Aquinas ↗