“And the scribes and chief priests heard it, and sought how they might destroy him: for they feared him, because all the people was astonished at his doctrine.”
Mark 11:18 — Greek Interlinear
Church Fathers on Mark 11:18
What the Lord had done in figure, when He cursed the barren fig tree, He now shews more openly, by casting out the wicked from the temple. For the fig tree was not in fault, in not having fruit before its time, but the priests were blameable; wherefore it is said, 'And they come to Jerusalem; and Jesus went into the temple, and began to cast out them that sold and bought in the temple.' Nevertheless, it is probable that He found them buying and selling in the temple things…
He calls moneychangers, changers of a particular sort of money, for the word means a small brass coin.
[This] according to Isaiah [Isa 56:7]. 'But ye have made it a den of thieves,' according to Jeremiah. [Jer 7:11]