Albert Barnes Commentary Micah 3:7

"And the seers shall be put to shame, and the diviners confounded; yea, they shall all cover their lips; for there is no answer of God." — Micah 3:7 (ASV)

They shall cover their lips - Literally, the hair of the upper lip. This was an action enjoined on lepers (Leviticus 13:45), and a token of mourning (Ezekiel 24:17, Ezekiel 24:22); a token then of sorrow and uncleanness. With their lips they had lied, and now they should cover their lips, as men mute and ashamed. For there is no answer of God, as these deceivers had pretended to have. When all things come contrary to what they had promised, it will be clear that God did not send them. And having plainly no answer of God, they will not dare to feign one then.

Jerome: “Then not even the devils will receive power to deceive them by their craft. The oracles will be mute; the unclean spirit will not dare to delude.” Dionysius: “All this is spoken against those who, in the Church of Christ, flatter the rich, or speak as menpleasers, out of avarice, ambition, or any like longing for temporal good, to whom that of Isaiah (Isaiah 3:12) applies; the leaders of this people (they who profess to lead them aright) mislead them, and those who are led of them are destroyed.”