Many are found to follow Leviticus (7)
I believe the answer is:
numbers
'many' is the definition.
(thesaurus)
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for numbers that I've seen before include "Book of Bible; counts" , "Principal features of mathematics" , "Quantities; Old Testament book" , "Fourth OT book - figures" , "Amounts; songs, etc" .)