Jeremiah 17:9

The heart [is] deceitful above all [things], and desperately wicked: who can know it?

Ver. 9. The heart of man is deceitful above all things.] The pravity and perversity of man's heart, full of harlotry and creature confidence, deceiving and being deceived, is here plainly and plentifully described; and oh that it were duly and deeply considered. "Deceitful" it is here said to be "above all things," no creature like it. Varium est, versutum, et versipelle; tortuosum est, anfractuosum et fallax, ideoque inscrutabile; It is full of turnings and windings, nooks and corners, wiles and sleights. It deceived David, as wise as he was, and tripped up his heels, as the word here used importeth; Psa 39:1-3 so it did Peter. Joh 13:37-38 Fitly doth the prophet here call our hearts "deceitful," in that word in the original, from whence Jacob had his name, because our fleshly hearts do the same things to the spirit in doing of good, which Jacob did to his brother - supplant it and catch it by the heel while it is running the Christian race. As Jehu offered sacrifice to Baal, killing his priests at the same time - and this he did in subtlety to circumvent them 2Ki 10:19 - and as Hushai went to Absalom's company to overthrow him, a so deal our deceitful hearts with us, &c. Neither is it deceitful only, but deep (so the Septuagint b here render it); those that are still digging in this dunghill do find it to be a very bottomless pit. Yea, it is

Desperately wicked.] Desperately bent upon deadly mischief. So that he gave no evil counsel who said to his friend, Ita cave tibi, ut caveas teipsum; so see to thyself that thou beware of thine own heart. Another prayed not amiss, Lord, keep me from that naughty man - myself. Take heed of the devil and the world, said a certain martyr in a letter to his wife, but especially of thine own heart.

“ Non longe scilicet hostes

Quaerendi nobis, circumstant undique muros. ”

We have a Trojan horse full of armed enemies in the citadel of our hearts. We have Jebusites enough within us to undo us, quos nec fugere possumus nec fugare. who we are not able to put to flight or rout. It was no ill character, therefore, of a good man that is given by Epictetus, a heathen, that he carefully watcheth himself as his own deadly enemy. c

Who can know it?] None but a man's self; 1Co 2:11 nor not even a man's self, for nothing is more common than self deceit. Gal 6:3 Jam 1:21 How much was Bellarmine, that great scholar, mistaken, and how ill-read in his own heart, when, the priest coming to absolve him on his deathbed, he could not remember any particular sin to confess till he went back in his thoughts as far as his youth! Had he but thrust his hand into his own bosom, with Moses, he had brought it out leprous, white as snow. Had he looked well into his own heart, he would have found it to be a raging sea of sin, Isa 57:20 where is that leviathan, the devil, besides creeping things, crawling lusts, innumerable. This made blessed Bradford never look on any man's lewd life but he would straight cry out, Lord, have mercy upon me! for in this my vile heart remaineth that sin which, without God's special grace, I should have committed as well as he.

a See Dike, Of the Deceitfulness of the Heart

b Bαθεια .

c ως εχθρον εαυτον παραφυλασσει και επιβουλον. - En. chirid, cap. 72.