Theophylact of Bulgaria
He calls moneychangers, changers of a particular sort of money, for the word means a small brass coin. There follows, and the seats of them that sold doves.
Further, He calls the temple, a den of thieves, on account of the money gained there; for thieves always troop together for gain. Since then they sold those animals which were offered in sacrifice for the sake of gain, He called them thieves.
But if a man by sinning gives up to the devil the grace and purity of baptism, he has sold his Dove, and for this reason is cast out of the temple. There follows, And would not suffer that any man should carry any vessel through the temple.
Which also turns to the greater condemnation of the Jews, because though the Lord did this so many times, nevertheless they did not correct their conduct.