שופטים, פרק י״ז, פסוק י״ב

A private household shrine requires dedicated leadership to function properly. When an opportunity arose to secure an official priest, Micah took formal steps to cement the relationship. He officially appointed the young Levite to this new religious position [ביאור שטיינזלץ]. This formal act of appointment explains why the Levite was previously described as becoming just like one of Micah's own sons [מצודת דוד].

The new role brought a major shift in the Levite's living situation. The primary approach among commentators is that prior to this, the young man was merely a temporary guest staying for a short time. However, once he was officially made a priest, his status shifted to that of a permanent resident who would remain in the home indefinitely [מלבי״ם, ביאור שטיינזלץ]. Thrilled by the success of securing a permanent priest for his household, Micah directed his praise toward the idol he kept in his possession [מלבי״ם].