Joshua 15:12

And the west border was to the great sea, and the coast thereof. This is the coast of the children of Judah round about according to their families.

Cross-reference

Joshua 15:47 also mentions the Great Sea as Judah's western border, identical to the boundary described here.

Numbers 34:6 commands the western border to be the Great Sea; here it is applied specifically to Judah's territory.

In Deuteronomy 34:2, Moses sees the land of Judah extending to the western sea, exactly as described here.

In Ezekiel 47:20, the western border of the land is also the Great Sea, echoing the same geographic description.