Control quantity of furniture in store (5)
I believe the answer is:
'control quantity' is the definition.
'reins' can be an answer for 'control' (take the reins). I'm not certain of the 'quantity' bit.
'of furniture in store' is the wordplay.
'of' indicates the answer is hidden within the clue.
'REINS' is hidden within 'furniture in store'.
Can you help me to learn more?
(Other definitions for reins that I've seen before include "Harnesses" , "Restrictions" , "Means of control for a horse" , "Guiding straps" , "Horse's controls" .)