דברי הימים ב, פרק כ״ג, פסוק ד׳

Jehoiada the Priest orchestrates a carefully designed strategy to protect the young King Joash and fulfill the will of God [ביאור שטיינזלץ]. To assemble a large armed force without drawing unwanted attention, he takes advantage of the weekly rotation of Priests and Levites at the Temple on the Sabbath. By using the natural transition of the guards, he is able to gather a significant number of men discreetly.

He outlines the operation, instructing the men on how the force will be divided. A third of the group [מצודת דוד, ביאור שטיינזלץ] is assigned to a specific post. These men are drawn from the incoming Sabbath shift, who are just beginning their Temple service [מצודת דוד, ביאור שטיינזלץ]. There are different views regarding the complete makeup of this protective force. One perspective suggests that Jehoiada held back the outgoing shift, combining them with the incoming guards and dividing the entire unified group into three units [רש״י]. Another approach explains that the incoming shift alone was divided into three units to guard the inner areas of the Temple, while the outgoing shift was stationed outside in the courtyards [מלבי״ם].

This specific third of the incoming guards is positioned as threshold keepers at a single, strategic location [ביאור שטיינזלץ]. The primary approach among commentators identifies this spot as the gathering house, located at the southern gate of the Temple courtyard, which is also known as the gate behind the guards [רד״ק, רלב״ג, מצודת ציון]. While their official post is to watch the doors, their true mission during this historic moment is to serve as the personal bodyguard for the new king [מצודת דוד].