Jamieson, Fausset and Brown on Micah 3:5

5. Here he attacks the false prophets, as before he had attacked the "princes."

make my people err--knowingly mislead My people by not denouncing their sins as incurring judgment.

bite with ... teeth, and cry, Peace--that is, who, so long as they are supplied with food, promise peace and prosperity in their prophecies.

he that putteth not into their mouths, they ... prepare war against him--Whenever they are not supplied with food, they foretell war and calamity.

prepare war--literally, "sanctify war," that is, proclaim it as a holy judgment of God because they are not fed (see on Jr 6:4; compare Is 13:3; Joe 1:14).