Collect petition (6)
I believe the answer is:
prayer
I believe this clue is a double definition.
'collect' is the first definition.
(thesaurus)
'petition' is the second definition.
('prayer' can be a synonym of 'petition')
(Other definitions for prayer that I've seen before include "An appeal to a deity" , "Paternoster, for example" , "Maybe collect" , "Request to deity" , "Invocation, entreaty" .)