John Chrysostom

As if He said, It is not yet time that My works should be preached, I require not thy preaching. By which He teaches us not to seek worldly honour as a reward for our works. It goes on: But go thy way, show thyself to the chief of the priests. Our Saviour sent him to the priest for the trial of his cure, and that he might not be cast out of the temple, but still be numbered with the people in prayer. He sends him also, that he might fulfil all the parts of the Law, in order to stop the evil-speaking tongue of the Jews. …

Catena Aurea by Aquinas ↗

Theophylact of Ohrid

And from this we are also taught not to make a show of ourselves when we do good to someone, for behold, Jesus Himself commands the one who was cleansed not to spread word about Him. Although He knew that the man would not listen and would spread the word, nevertheless, as I said, teaching us not to love vainglory, He commands him to tell no one.

Commentary on Mark ↗

Bede

And he immediately threatened him and cast him out, etc. Why is it commanded to tell no one, except to indicate that our benefits are not to be publicized, but kept hidden, so that we refrain not only from the reward of money but also from praise.

On the Gospel of Mark ↗