Albert Barnes Commentary 1 Kings 22:11

"And Zedekiah the son of Chenaanah made him horns of iron, and said, Thus saith Jehovah, With these shalt thou push the Syrians, until they be consumed." — 1 Kings 22:11 (ASV)

Horns of iron - The horn in Scripture is the favorite symbol of power, and pushing with the horn is a common metaphor for attacking and conquering enemies (Daniel 8:4). Zedekiah, in employing a symbolic action, was following the example of a former Israelite prophet (1 Kings 11:30).

Thus saith the Lord - Or, יהוה y^ehovâh. Zedekiah lays aside the unmeaningful “Lord” (אדני 'ǎdonāy) of the general company of Israelite prophets (1 Kings 22:6) and professes to have a direct message from Yahweh to Ahab. He may have believed his own words, for the lying spirit (1 Kings 22:22) may have seemed to him a messenger from Yahweh. All the rest followed his example (1 Kings 22:12).