Spoke briefly about hot Biblical site (5)
I believe the answer is:
sinai
'biblical site' is the definition.
(Mount Sinai in the Bible)
'spoke briefly about hot' is the wordplay.
'spoke' becomes 'said' (I've seen this before).
'briefly' means to remove the last letter.
'about' indicates putting letters inside.
'hot' becomes 'in' (both can mean fashionable).
'said' with its last letter taken away is 'sai'.
'sai' enclosing 'in' is 'SINAI'.
(Other definitions for sinai that I've seen before include "Part of 10 [EGYPT]" , "Mountainous peninsula in Egypt" , "Egyptian location" , "Mt. where Moses received 10 Commandments" , "Peninsula, mostly desert, at north end of Red Sea" .)