Peninsula north of the Red Sea (5)
I believe the answer is:
sinai
'peninsula north of the red sea' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for sinai that I've seen before include "Mountain source of Mosaic Law" , "Mountain in Egypt" , "Mountainous peninsula in Egypt" , "Mt. where Moses received 10 Commandments" , "Ten Commandments mountain" .)