Matthew
Matthew 3:10ESV·traditional attribution

Even now the axe is laid to the root of the trees. Every tree therefore that does not bear good fruit is cut down and thrown into the fire.

John Calvin Reformed @genevareformer

Matthew 3:10; Luke 3:9. And now also the axe. After having stripped hypocrites of the covering of a vain confidence, John announces the approaching judgment of God. He had formerly said that, though they were rejected, God would not want a people: and he now adds, that God is just about to drive out unworthy persons from the Church, as barren trees are wont to be cut down.

Matthew Henry Presbyterian @wholebiblehenry

The doctrine John preached was that of repentance, in consideration of the kingdom of heaven being at hand; now here we have the use of that doctrine. Application is the life of preaching, so it was of John's preaching. Observe, 1. To whom he applied it; to the Pharisees and Sadducees that came to his baptism, Mat 3:7.

Commenting on Matthew 3:7-12

John Gill Reformed Baptist @doctorgill

And now also the axe is laid,.... These words may be rendered, "for now also", and contain in them a reason why they might expect future wrath; why they should bring forth good fruit; and why they should not trust to nor plead their descent from Abraham, because "the axe is now laid": by which is meant, not the Gospel which now began to be...