Therefore thus saith the LORD, If thou return, then will I bring thee again, and thou shalt stand before me: and if thou take forth the precious from the vile, thou shalt be as my mouth: let them return unto thee; but return not thou unto them.
God's reply to Jeremiah.
If thou return, then will I bring thee again. Jeremiah, by his impatient language, had left his proper posture toward God; God saith, "If thou wilt return (to thy former patient discharge of thy prophetic function), I will bring thee back" to thy former position: in the Hebrew there is a play of words, "return ... turn again" (Jeremiah 8:4; Jeremiah 4:1).
Thou shalt stand before me - minister acceptably to me (Deuteronomy 10:8; 1 Kings 17:1; 1 Kings 18:15).
If thou take forth the precious from the vile - image from metals: 'If thou wilt separate what is precious in thee (the divine graces imparted) from what is vile (thy natural corruptions, impatience, and hasty words), thou shalt be as my mouth:' my mouthpiece (Exodus 4:16).
Return not thou unto them - let not them lead you into their profane ways (as Jeremiah had spoken irreverently, Jeremiah 15:18), but lead thou them to the ways of godliness (Jeremiah 15:16-17). Ezekiel 22:26 ("They have put no difference between the holy and profane") accords with the other interpretation, which however, does not so well suit the context, 'If thou wilt separate from the promiscuous mass the better ones, and lead them to conversion by faithful warnings,' etc.