Sharp cross from Metatron say in holy books returned (7)
I believe the answer is:
tangelo
'sharp cross' is the definition.
(I've seen this before)
'metatron say in holy books returned' is the wordplay.
'metatron say' becomes 'angel' (angel in Judaism).
'in' indicates putting letters inside.
'holy books' becomes 'OT' (Old Testament).
'returned' says the letters should be written in reverse.
'ot' in reverse letter order is 'to'.
'angel' put inside 'to' is 'TANGELO'.
'from' is the link.
(Other definitions for tangelo that I've seen before include "Mixed fruit" , "Hybrid fruit; eat long (anag.)" , "one cross, sour" , "sharp cross" , "Citrus hybrid - goal net (anag)" .)