Yeremia 17:9

17:9 The human mind is more deceitful than anything else.

It is incurably bad. ¹  Who can understand it?

Ibrani 3:13

3:13 But exhort one another each day, as long as it is called “Today,” that none of you may become hardened by sin’s deception.

¹ tn Or “incurably deceitful”; Heb “It is incurable.” For the word “deceitful” compare the usage of the verb in Gen 27:36 and a related noun in 2 Kgs 10:19. For the adjective “incurable” compare the usage in Jer 15:18. It is most commonly used with reference to wounds or of pain. In Jer 17:16 it is used metaphorically for a “woeful day” (i.e., day of irreparable devastation).

sn The background for this verse is Deut 29:18-19 (29:17-18 HT) and Deut 30:17.