They do not take anything from the share of the collectors as wages for the work

Sayyiduna Abd al-Muttalib bin Rabi'ah bin al-Harith (may Allah be pleased with him) said: Sayyiduna Rabi'ah bin al-Harith and Sayyiduna Abbas (may Allah be pleased with them both) consulted together and said: "If we send these two boys, that is, me and al-Fadl, to the Messenger of Allah (peace and blessings be upon him), they could speak to the Messenger of Allah (peace and blessings be upon him) and he (peace and blessings be upon him) might appoint them as collectors over the charities, so that they would do the work that people do and receive the share that people receive." While they were talking about this, Sayyiduna Ali (may Allah be pleased with him) came to them, and they spoke to him about it. He said: "Do not do it; by Allah, he is not going to do it." Sayyiduna Rabi'ah bin al-Harith (may Allah be pleased with him) turned to him and said: "By Allah, you are only doing this out of envy towards us. By Allah, you became the son-in-law of the Messenger of Allah (peace and blessings be upon him) and we did not envy you for it." Sayyiduna Ali (may Allah be pleased with him) said: "I am Abu al-Hasan, the chief of the people. Send them." So the two of them set off, and Ali lay down. When the Prophet (peace and blessings be upon him) had led the prayer, we hurried to the apartment and stood there. He (peace and blessings be upon him) took hold of us by our ears and said: "Bring out what you have in mind." Then he (peace and blessings be upon him) went inside, and we went in with him (peace and blessings be upon him). That day he (peace and blessings be upon him) was with Sayyidah Zaynab bint Jahsh (may Allah be pleased with her). We intended to speak, and one of us said: "O Messenger of Allah, you are the most trustworthy of people and the one who most joins the ties of kinship. We have reached marriageable age, and we have come to you so that you may put us to some work over the charities; then we will also bring you the wealth that people bring, and we will receive the share that people receive." He (peace and blessings be upon him) remained silent. We intended to speak again, but Sayyidah Zaynab (may Allah be pleased with her) signalled to us from behind the curtain to remain silent. Then he (peace and blessings be upon him) said: "Indeed, charity is not permissible for the family of Muhammad (peace and blessings be upon him); it is only the dirt of people." Then he (peace and blessings be upon him) summoned Sayyiduna Mahmiyah (may Allah be pleased with him), who was in charge of the khumus (one-fifth), and summoned Sayyiduna Nawfal bin al-Harith bin Abd al-Muttalib (may Allah be pleased with him). He (peace and blessings be upon him) said to Sayyiduna Mahmiyah (may Allah be pleased with him): "Marry your daughter to this young man, al-Fadl bin Abbas (may Allah be pleased with them both)," and he married her to him. And he said to Sayyiduna Nawfal bin al-Harith (may Allah be pleased with him): "Marry your daughter to this young man" (meaning me), and he married her to me. Then he said to Sayyiduna Mahmiyah (may Allah be pleased with him): "Give them such-and-such from the khumus (as their dowry)."

Ibn Shihab al-Zuhri (may Allah have mercy on him) says in the hadith that he (peace and blessings be upon him) said to us: "Charity is the dirt of people, and it is permissible neither for Muhammad (peace and blessings be upon him) nor for his family."

Likewise (through another chain).