דברי הימים ב, פרק י״ח, פסוק כ״א

In the heavenly court, a plan is set into motion to bring about the downfall of King Ahab. A spirit steps forward, volunteering to deceive the king and lure him into a fatal battle, and God grants approval for this mission. The spirit plans to carry out this deception through the physical act of speech, which is formed by breath and expelled air [מצודת ציון]. It declares that it will become a lying presence in the mouths of all the king's prophets, planting a false promise of guaranteed military victory to mask the reality that the king is actually marching toward his defeat.

This method reveals a surprising detail about the prophets themselves. The very fact that the spirit needs to actively place these false words into their mouths indicates that they were fundamentally true prophets. Until this moment, they were accustomed to speaking only the authentic messages that God provided to them [רש״י].

God accepts the spirit's proposal, assuring it that the deception will be fully executed and successful [מצודת ציון]. Often, when someone tries to lure another person into a trap, the target might sense a hidden motive and pull back. In this case, however, the deception will be absolute. The king will be completely taken in by the false promises and will confidently march out to war [רש״י, מצודת דוד]. With the plan confirmed, God urges the spirit to depart immediately and put the deception into action [מצודת דוד].