Ibn as-Sa‘idi said

‘Umar employed me to collect the sadaqa, and when I finished doing so and gave it to him he ordered payment to be given me, but I said, “I did it only for Allah’s sake, and my reward will come from Allah.” He replied, “Take what you are given, for I acted as a collector in the time of Allah's Messenger ﷺ, and when he assigned me a payment I said the same kind of thing as you have said, to which he replied that when I was given something without asking for it I should use it for my own purposes and as sadaqa.” Abu Dawud transmitted it.