Expositor's Bible Commentary Commentary Matthew 3:10

"And even now the axe lieth at the root of the trees: every tree therefore that bringeth not forth good fruit is hewn down, and cast into the fire." — Matthew 3:10 (ASV)

The ax is “already” at the root of the trees (for the idiom, cf. Isaiah 10:33–34; Jeremiah 46:22). Just as the kingdom is dawning already (v.2), so also is the judgment; the two are inseparable. To preach the kingdom is to preach repentance; any tree, regardless of its roots, that does not bring forth good fruit will be destroyed.