שופטים, פרק ט׳, פסוק ו׳

The residents of Shechem and the nearby area of Beth-millo come together with a unified purpose: to officially crown Abimelech as the ruler over their city and the surrounding region [ביאור שטיינזלץ].

The coronation ceremony is held at a specific geographic landmark. The gathering takes place physically close to a site known as Elon Mutzav, which is a distinct, flat plain [ביאור שטיינזלץ]. Relying on early Aramaic translations, the primary approach among commentators is that this plain was home to a large stone, a monument, or another highly visible object. Because this structure was so prominent, the entire surrounding plain eventually took on the name of the monument that stood firmly within it [רש״י, רלב״ג, רד״ק].