Jezebel designs a public conspiracy to seal Naboth’s fate, hiding a planned execution behind the appearance of a formal religious and legal process. She sends out written instructions as her own personal advice rather than issuing them in the name of King Ahab. While the king’s written claim that Naboth cursed him and God would technically be enough to condemn him, a public execution requires face-to-face testimony. Since it would damage the king's honor to personally testify against a man who insulted him, Jezebel suggests staging a public trial [מלבי״ם].
To set this plan in motion, she calls for a fast. The primary approach among commentators is that this refers to an actual day of fasting. Traditionally, on these days, the city elders and the public would gather to examine their behavior, uncover any sins within the community, and make amends [רש״י, מצודת דוד, רד״ק]. This large gathering creates the perfect environment, providing a full audience for false witnesses to testify against Naboth [רלב״ג]. Alternatively, some explain that this call does not involve abstaining from food at all, but is simply a formal way to announce a mass public assembly [רד״ק, ביאור שטיינזלץ].
During this gathering, Naboth is to be placed at the head of the people. Because he was a highly respected man, giving him the most important seat creates a false impression that he is honored and loved by the community, right before the sudden accusation is made against him [ביאור שטיינזלץ]. Another view suggests that placing him at the head means raising him onto a high platform. This was the standard practice for people on trial for their lives, ensuring that the entire crowd could clearly see the accused as the trial unfolded [מלבי״ם].