דברי הימים ב, פרק כ״ט, פסוק ט״ז

The purification of God's Sanctuary required strict adherence to a precise division of labor, dictated by the laws of holiness and strict entry restrictions. The removal of the idols unfolded in careful stages, transferring responsibility from the innermost areas to the outside. Because the law permitted only the priests to enter the inner Sanctuary, they alone went inside to purify the space, while the Levites were forbidden from entering [מצודת דוד]. Inside, the priests uprooted and smashed the various idols and statues that defiled the holy site [מצודת דוד, ביאור שטיינזלץ].

Once the idols were destroyed, the priests carried the debris out to the Temple courtyard. This courtyard served as the permitted standing area for the Levites. Unable to enter the Sanctuary themselves, the Levites waited outside to receive the remains of the impurity from the hands of the priests [רש״י, מצודת דוד]. Taking over the final stage of the task, the Levites then carried the broken idols away to the Kidron Valley, ensuring the impurity was completely removed beyond the city limits [מצודת דוד].