Joshua 15:2
And their south border was from the shore of the salt sea, from the bay that looketh southward:
Cross-reference
Joshua 18:19 mentions the northern bay of the Salt Sea, contrasting with the southern bay here — both ends of the same sea.
Joshua 12:3 lists the Salt Sea region among conquered territories, providing context for this border's role in the conquest.
Numbers 34:3 gives the same southern boundary starting point for Canaan, directly paralleling the border description for Judah.
Genesis 14:3 identifies the Valley of Siddim as the Salt Sea, providing the origin of this geographical marker for Judah's southern border.
Deuteronomy 3:17 also mentions the Salt Sea as a boundary marker for the Transjordan tribes, paralleling this usage.
Ezekiel 47:18 also uses the Salt Sea as an eastern border marker, complementing the southern boundary starting point here.