Note, 1. The hearts of the children of men are subject, not only to God's view, but to his judgment: As the fining-pot is for silver, both to prove it and to improve it so the Lord tries the hearts; he searches whether they are standard or no, and those that are he refines and makes purer, Jer 17:10. God tries the heart by affliction (Psa 66:10, Psa 66:11), and often chooses his people in that furnace (Isa 48:10) and makes them choice. 2. It is God only that tries the hearts. Men may try their silver and gold with the fining-pot and the furnace, but they have no such way of trying one another's hearts; God only does that, who is both the searcher and the sovereign of the heart.

The fining pot is for silver, and the furnace for gold,.... Refiners of silver have their fining pots, in which they purify the silver from the dross; and goldsmiths have their crucibles to melt and purify their gold, by which assays of the worth and value of it may be made;

but the Lord trieth the hearts; there is no vessel, as Gersom observes, in which they can be put and tried by creatures; a man does not know, nor can he thoroughly search and try his own heart, and much less the hearts of others; God only knows and tries them, Jer 17:9; The Septuagint, Vulgate Latin, and Arabic versions, render it by way of similitude, "as the fining pot is for silver", &c. as silver is refined in the pot, and gold in the furnace, so are the hearts of God's people, and their graces tried and purified by him in the furnace of affliction; the variety of troubles they are exercised with are made useful for the purging away of the dross of sin and corruption, and for the brightening of their graces, Pe1 1:7.

God only knows, as He tries (Psa 12:6; Psa 66:10) the heart.