In the Bible, he takes Aaron’s staff (5)
I believe the answer is:
herod
'in the bible he takes aaron's staff' is the definition.
The definition suggests a singular noun which matches the answer.
'he takes aaron's staff' is the wordplay.
'takes' means one lot of letters go next to another.
'aaron's staff' becomes 'rod' (I can't explain this - if you can you should believe this answer much more).
'he'+'rod'='HEROD'
Can you help me to learn more?
(Other definitions for herod that I've seen before include "Biblical king of Judea" , "Roman king of Judaea" , "King of Judaea, temple builder" , "NT king" , "Ruler of Palestine when Jesus was born" .)