Jamieson, Fausset and Brown on Amos 7:12

12. Also--Besides informing the king against Amos, lest that course should fail, as it did, Amaziah urges the troublesome prophet himself to go back to his own land Judah, pretending to advise him in friendliness.

seer--said contemptuously in reference to Amos' visions which precede.

there eat bread--You can earn a livelihood there, whereas remaining here you will be ruined. He judges of Amos by his own selfishness, as if regard to one's own safety and livelihood are the paramount considerations. So the false prophets (Eze 13:19) were ready to say whatever pleased their hearers, however false, for "handfuls of barley and pieces of bread."