Collect dull rug (6,3)

I believe the answer is:

prayer mat

'rug' is the definition.
(prayer mat is a kind of rug)

'collect dull' is the wordplay.
'collect' becomes 'prayer' (I've seen this before).
'dull' becomes 'mat' ('mat' can be similar in meaning to 'dull'**).
'prayer'+'mat'='PRAYER-MAT'

(Other definitions for prayer mat that I've seen before include "one goes down in supplication" , "One going to Mecca may have one" , "devotional base" , "Arabian carpet?" , "Rug" .)

I've seen this clue in The Telegraph.

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