A collection of service people perhaps (9)

I believe the answer is:

offertory

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'a collection' is the definition.
(I've seen this before)

I can't explain the rest of the clue.

(Other definitions for offertory that I've seen before include "Church collection" , "part of church service" , "Fry to fore at this part of church ceremony" , "Donation" , "Money collected during church service" .)

I've seen this clue in The Globe and Mail.

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