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 References (ranked by relevance)
Ezekiel 47:20
The west side also shall be the great sea from the border, till a man come over against Hamath. This is the west side.
Joshua 15:47
Ashdod with her towns and her villages, Gaza with her towns and her villages, unto the river of Egypt, and the great sea, and the border thereof:
Deuteronomy 11:24
Every place whereon the soles of your feet shall tread shall be yours: from the wilderness and Lebanon, from the river, the river Euphrates, even unto the uttermost sea shall your coast be.