יהושע, פרק ט״ו, פסוק ב׳

The allocation of land for the tribe of Judah begins by tracing its southern boundary, establishing a clear line that stretches from east to west [רש״י, מצודת דוד, ביאור שטיינזלץ]. The starting point for this territory is located at the edge of the Dead Sea. This specific area marks the southeastern corner of the Land of Israel, serving as the exact location where the Wilderness of Zin begins [רש״י, מצודת דוד].

From this starting point, the boundary originates precisely from a natural feature shaped like a tongue. The primary approach among commentators is that this refers to a geographic extension of the sea itself, where a strip of water protrudes outward and faces south. However, an alternative perspective views this natural landmark not as a body of water, but rather as a distinct, protruding rock formation that naturally takes the physical shape of a tongue [חומת אנך].