Ecclesiastes 1:15

[That which is] crooked cannot be made straight,.... By all the art and cunning, wisdom and knowledge of man, that he can attain unto; whatever he, in the vanity of his mind, may find fault with in the works of God, either of nature of providence, and which he may call crooked, it is not in his power to make them straight, or to mend them; see Ecclesiastes 7:13. There is something which, through sin, is crooked, in the hearts, in the nature, in the principles, ways and works, of men; which can never be made straight, corrected or amended, by all the natural wisdom and knowledge of men, which shows the insufficiency of it: the wisest philosophers among men, with all their parade of wit and learning, could never effect anything of this kind; this only is done by the Spirit and grace of God; see Isaiah 42:16;

and that which is wanting cannot be numbered; the deficiencies in human science are so many, that they cannot be reckoned up; and the defects in human nature can never be supplied or made up by natural knowledge and wisdom; and which are so numerous, as that they cannot be understood and counted. The Targum is,

"a man whose ways are perverse in this world, and dies in them, and does not return by repentance, he has no power of correcting himself after his death; and a man that fails from the law and the precepts in his life, after his death hath no power to be numbered with the righteous in paradise:''

to the same sense Jarchi's note and the Midrash.