Proverbs 24:2 (BSB)

for their hearts devise violence, and their lips declare trouble.

From Proverbs 24. Also in the ESV.

Commentary on Proverbs 24:2

• John Gill (Reformed Baptist), Exposition of the Old and New Testaments on Proverbs 24:2: For their heart studieth destruction,.... To others; to good men, that separate from them, and reprove them, or are in their way; or any ways hinder them in the prosecution of their wicked designs; as Haman's heart studied the destruction of the Jews: or their hearts study to draw men into their destructive methods of living, and therefore should be shunned and avoided.
• Jamieson-Fausset-Brown (Reformed), Commentary Critical and Explanatory on the Whole Bible on Proverbs 24:2: studieth--meditateth. talk . . . mischief--Their expressed purposes are to do evil.
• Geneva Bible Notes (Reformed), Geneva Bible Study Notes on Proverbs 24:1-6: They have stricken me, [shalt thou say, and] I was not sick; they have beaten me, [and] I felt [it] not: when shall I awake? I will seek it yet again. (q) Though drunkenness makes them more insensible then beasts, yet they can not refrain.
• Keil & Delitzsch (Lutheran), Biblical Commentary on the Old Testament on Proverbs 24:1-2: Pro 24:1-2 After this divergence (in Pro 23:29-35) from the usual form of the proverb, there is now a return to the tetrastich: 1 Envy not evil men, And desire not to have intercourse with them. 2 For their heart thinketh of violence, And their lips speak mischief.