Proverbs 11:9 (BSB)

With his mouth the ungodly man destroys his neighbor, but through knowledge the righteous are rescued.

From Proverbs 11. Also in the ESV.

Commentary on Proverbs 11:9

• Matthew Henry (Presbyterian), Matthew Henry's Complete Commentary on Proverbs 11:9: Here is, 1. Hypocrisy designing ill. It is not only the murderer with his sword, but the hypocrite with his mouth, that destroys his neighbour, decoying him into sin, or into mischief, by the specious pretences of kindness and good-will. Death and life are in the power of the tongue, but no tongue more fatal than the flattering tongue. 2.
• John Gill (Reformed Baptist), Exposition of the Old and New Testaments on Proverbs 11:9: An hypocrite with his mouth destroyeth his neighbour,.... Deceives him with his flatteries and lies, and draws him into destructive schemes and practices; or "corrupts" him, as the word (i) signifies, and as the Targum renders it, with false doctrines; so, with fair words and good speeches, such who lie in wait to deceive impose upon the simple and credulous; and false teachers, with their...
• Jamieson-Fausset-Brown (Reformed), Commentary Critical and Explanatory on the Whole Bible on Proverbs 11:9: (Compare Psa 35:16; Dan 11:32). The just is saved by superior discernment.
• Geneva Bible Notes (Reformed), Geneva Bible Study Notes on Proverbs 11:9: An hypocrite with [his] mouth destroyeth his neighbour: but through knowledge shall the just be delivered. (d) A deceiver who pretends friendship, but privately is an enemy.