12 The west border was to the shore of the great sea. This is the border of the children of Judah according to their families.
Joshua 15:12 Cross References - WEB
Numbers 34:6-7
Deuteronomy 11:24
24 Every place on which the sole of your foot treads shall be yours: from the wilderness and Lebanon, from the river, the river Euphrates, even to the western sea shall be your border.
Joshua 15:47
47 Ashdod, its towns and its villages; Gaza, its towns and its villages; to the brook of Egypt, and the great sea with its coastline.
Ezekiel 47:20
20 “The west side shall be the great sea, from the south border as far as opposite the entrance of Hamath. This is the west side.