Musnad Ahmad 495:0

Narrated by ‘Abd al-Muṭṭalib ibn Rabī‘ah ibn al-Ḥārith ibn ‘Abd al-Muṭṭalib: He said: Al-Faḍl ibn al-‘Abbās and I went to the Messenger of Allah (ﷺ). One of us said to the other, "By Allah, if we go to the Messenger of Allah (ﷺ) and speak to him, and he appoints us over some of these charities, we will collect them and pay them out, and we will acquire what the people acquire." The other said, "By Allah, I will not do that." So we went to him, and he was in a garden. We greeted him, and he returned our greeting. Then he looked at us for a long time, then he called us, and we came to him. He said, "I have heard what you said." Then he said, "Verily, these charities are only the impurities of people’s wealth, and they are not permissible for Muḥammad nor for the family of Muḥammad."