Numbers 34:3

The southern border will extend from the wilderness of Zin along the border of Edom. It will begin on the east at the southern end of the Dead Sea.

Genesis 14:3

These joined forces in the Valley of Siddim at the Dead Sea.

Ezekiel 47:13

This is what the Lord Jehovah says: These are the borders of the land that is to be divided among the twelve tribes of Israel. Joseph gets two parts.

Exodus 23:31

I will make the borders of your land extend from the Gulf of Aqaba to the Mediterranean Sea and from the desert to the Euphrates River. I will give you power over the inhabitants of the land. You will drive them out as you advance.

Joshua 3:16

The waters stood and rose up upon a heap very far from the city Adam that is beside Zaretan. The waters that came down toward the sea of the plain, even the salt sea, failed, and were cut off. The people passed over the Jericho.

Joshua 15:1-12

This then was the lot of the tribe of the children of Judah by their families: The border of Edom the wilderness of Zin southward was the farthest part of the south coast.

Ezekiel 47:8

He said: This water flows through the land to the east, down into the Jordan Valley, and into the Dead Sea. When the water flows into the Dead Sea, it will replace the salt water there with fresh water.

Ezekiel 47:18-23

On the east side the border will run between Hauran and Damascus. The Jordan River will serve as the border between Gilead and the land of Israel. The border will continue from the Dead Sea down to Tamar. This is the east side.

Treasury of Scripture Knowledge

Summary

Then your south quarter shall be from the wilderness of Zin along by the coast of Edom, and your south border shall be the outmost coast of the salt sea eastward:

Bible References

South quarter

Exodus 23:31
I will make the borders of your land extend from the Gulf of Aqaba to the Mediterranean Sea and from the desert to the Euphrates River. I will give you power over the inhabitants of the land. You will drive them out as you advance.
Joshua 15:1
This then was the lot of the tribe of the children of Judah by their families: The border of Edom the wilderness of Zin southward was the farthest part of the south coast.
Ezekiel 47:13
This is what the Lord Jehovah says: These are the borders of the land that is to be divided among the twelve tribes of Israel. Joseph gets two parts.

Salt sea eastward

Joshua 3:16
The waters stood and rose up upon a heap very far from the city Adam that is beside Zaretan. The waters that came down toward the sea of the plain, even the salt sea, failed, and were cut off. The people passed over the Jericho.
Joshua 15:2
The shore of the salt sea was their south border, from the bay that looks southward:
Ezekiel 47:8
He said: This water flows through the land to the east, down into the Jordan Valley, and into the Dead Sea. When the water flows into the Dead Sea, it will replace the salt water there with fresh water.