The answer to the question, "who can know it?" To himself a man's heart is an inscrutable mystery: God alone can fathom it.

Ways - Rather, way, his course of life. The "and" must be omitted, for the last clause explains what is meant "by man's way," when he comes before God for judgment. It is "the fruit," the final result "of his doings, i. e., his real character as formed by the acts and habits of his life.

I the Lord search the heart - The Lord is called by his apostles, Acts 1:24, Καρδιογνωστης, the Knower of the heart. To him alone can this epithet be applied; and it is from him alone that we can derive that instruction by which we can in any measure know ourselves.

I the Lord search the heart,.... The inward parts of it, every room and corner in it; and know the thoughts of it; all its intents, purposes, designs, contrivances, and imaginations; all the secret motions of it, and the wickedness that is in it; so that this is an answer to the question in the preceding verse; and therefore, though the heart is deceitful, it cannot deceive him, because he judges not according to outward appearance; he sees and knows the heart; and none but the Lord, or he who is Jehovah, can so search the heart as thus to know it; wherefore, since Christ is said to search the reins and the heart, and to know the thoughts of men, and to be a discerner of the thoughts and intents of the heart, he must be Jehovah, and the true God, Revelation 2:23,

I try the reins; the most inward and remote parts, covered with fat, and out of sight: these are the seat of the affections; and the Lord tries these, whether they are towards him or not; and whether sincere or hypocritical; Christ the omniscient God knew Peter's love to him, and the sincerity of it; for which he appeals to him as such, John 21:17,

even to give every man accordions to his ways, and according to the fruit of his doings; to do which it is necessary to search the heart, and try the reins, the fountain of all actions; and in which the principles of them are, and according to which they are denominated and judged of: in the future judgment every secret thing will be brought into account; the counsels of the heart will be made manifest; the book of conscience will be opened; and out of it, as well as other books, men will be judged according to their ways and works; and therefore it is requisite that the Judge should be the Lord God omniscient, the searcher and trier of the hearts and reins, as Christ is.

Only God searches the heart and tries the reins, the seat of the most hidden emotions and feelings, cf. Jeremiah 11:20; Jeremiah 12:3, and deals accordingly, requiting each according to his life and his doings. The ו before לתת, which is wanting in many MSS and is not expressed by the old translators, is not to be objected to. It serves to separate the aim in view from the rest, and to give it the prominence due to an independent thought; cf. Ew. 340, b. As to the truth itself, cf. Jeremiah 32:19. With this is joined the common saying as to the partridge, Jeremiah 17:11. The aim is not to specify greed as another root of the corruption of the heart, or to give another case of false confidence in the earthly (Ng., Graf); but to corroborate by a common saying, whose truth should be obvious to the people, the greater truth, that God, as Searcher of hearts, requites each according to his works. The proverb ran: He that gains riches, and that by wrong, i.e., in an unjust, dishonourable manner, is like a partridge which hatches eggs it has not laid. In the Proverbs we often find comparisons, as here, without the כּ similit.: a gainer of riches is a partridge (Rephuhn, properly Rphuhn from rpen equals rufen, to call or cry); a bird yet found in plenty in the tribe of Judah; cf. Robinson, Palestine. All other interpretations are arbitrary. It is true that natural history has not proved the fact of this peculiarity of the partridge, on which the proverb was founded; testimonies as to this habit of the creature are found only in certain Church fathers, and these were probably deduced from this passage (cf. Winer, bibl. R. W., art. Rebhuhn). But the proverb assumes only the fact that such was the widespread popular belief amongst the Israelites, without saying anything as to the correctness of it. "HatCheth and layeth not" are to be taken relatively. דּגר, the Targum word in Job 39:14 for חמּם, fovere, sig. hatch, lit., to hold eggs close together, cover eggs; see on Isaiah 34:15. ילד, to bring forth, here of laying eggs. As to the Kametz in both words, see Ew. 100, c. The point of the comparison, that the young hatched out of another bird's eggs forsake the mother, is brought out in the application of the proverb. Hence is to be explained "forsake him:" the riches forsake him, instead of: are lost to him, vanish, in the half of his days, i.e., in the midst of life; and at the end of his life he shall be a fool, i.e., the folly of his conduct shall fully appear.

I the LORD search the heart, I try the reins, even to give every man according to his ways, and according to the fruit of his doings.

10. Lest any should infer from Jer 17:9, "who can know it?" that even the Lord does not know, and therefore cannot punish, the hidden treachery of the heart, He says, "I the Lord search the heart," &c. (1Ch 28:9; Ps 7:9; Pr 17:3; Re 2:23).

even to give-and that in order that I may give (Jer 32:19).

17:5-11 He who puts confidence in man, shall be like the heath in a desert, a naked tree, a sorry shrub, the product of barren ground, useless and worthless. Those who trust to their own righteousness and strength, and think they can do without Christ, make flesh their arm, and their souls cannot prosper in graces or comforts. Those who make God their Hope, shall flourish like a tree always green, whose leaf does not wither. They shall be fixed in peace and satisfaction of mind; they shall not be anxious in a year of drought. Those who make God their Hope, have enough in him to make up the want of all creature-comforts. They shall not cease from yielding fruit in holiness and good works. The heart, the conscience of man, in his corrupt and fallen state, is deceitful above all things. It calls evil good, and good evil; and cries peace to those to whom it does not belong. Herein the heart is desperately wicked; it is deadly, it is desperate. The case is bad indeed, if the conscience, which should set right the errors of other faculties, is a leader in the delusion. We cannot know our own hearts, nor what they will do in an hour of temptation. Who can understand his errors? Much less can we know the hearts of others, or depend upon them. He that believes God's testimony in this matter, and learns to watch his own heart, will find this is a correct, though a sad picture, and learns many lessons to direct his conduct. But much in our own hearts and in the hearts of others, will remain unknown. Yet whatever wickedness there is in the heart, God sees it. Men may be imposed upon, but God cannot be deceived. He that gets riches, and not by right, though he may make them his hope, never shall have joy of them. This shows what vexation it is to a worldly man at death, that he must leave his riches behind; but though the wealth will not follow to another world, guilt will, and everlasting torment. The rich man takes pains to get an estate, and sits brooding upon it, but never has any satisfaction in it; by sinful courses it comes to nothing. Let us be wise in time; what we get, let us get it honestly; and what we have, use it charitably, that we may be wise for eternity.