Joshua 15:4
From thence it passed toward Azmon, and went out unto the river of Egypt; and the goings out of that coast were at the sea: this shall be your south coast.
Cross-references
Numbers 34:5
Parallel
Numbers 34:5 gives the same southern boundary from Azmon to Brook of Egypt, confirming the tribal allotment matches the national border.
Genesis 15:18
Prophetic fulfillment
Genesis 15:18 promises the land from the river of Egypt, fulfilled here as the Brook of Egypt marking Judah's border.
2 Kings 24:7
Parallel
2 Kings 24:7 uses the same 'Brook of Egypt' as a territorial boundary — reinforcing the same landmark.