1 Kings 22:13
And the messenger that was gone to call Micaiah spake unto him, saying, Behold now, the words of the prophets declare good unto the king with one mouth: let thy word, I pray thee, be like the word of one of them, and speak that which is good.
The king's prophets spoke with one mouth, all declaring favorably toward the king and promising Ahab success. The messenger sent to call Micaiah pressed him to agree with those prophets and to speak what is good like the word of one of them. Ahab stood opposed to Micaiah because Micaiah prophesied evil against him rather than good.
Micaiah refused to join the favorable chorus and instead warned that Israel would be scattered. The unanimous message of success did not change the truth of what God had revealed. The battle that followed ended in Ahab's death, fulfilling Micaiah's warning.