Your border will turn south of the Ascent of Akrabbim, proceed to Zin, and end south of Kadesh-barnea. It will go to Hazar-addar and proceed to Azmon.

Then the border will go to Ziphron and end at Hazar-enan. This will be your northern border.

For your eastern border, draw a line from Hazar-enan to Shepham.