Musnad Ahmad #350

It was narrated that Ibn as Sa`idi al-Maliki said: `Umar bin al Khattab (رضي الله عنه) appointed me in charge of the zakah, and when had finished with it and handed it over to him, he ordered that I be given some remuneration. I said: I only did it for the sake of Allah and my reward is with Allah. He said: Take what is given to you. I was appointed to do some work at the time of the Messenger of Allah (ﷺ) and he gave me some remuneration, and I said the same as you have said, but the Messenger of Allah (ﷺ) said to me: `If you are given something without asking for it, then take it and give some in charity.”