Sahih al-Bukhari 7163

Huwaytib ibn 'Abdu'l-'Uzza reported that 'Abdullah ibn as-Sa'di reported that he went to 'Umar while he was khalif and 'Umar said to him, "Have I not been told that you undertake public office, but when you are given wages, you refuse to take that?" [He said,] "I answered, 'Yes.' 'Umar asked, 'Why do you do that?' I replied, 'I have horses and slaves and I am well-off. I wish for my wages to be sadaqa for the Muslims.' 'Umar said, 'Do not do it. I wanted to do what you want to do. The Messenger of Allah, may Allah bless him and grant him peace, used to give Me gifts and I used to say, 'Give it to someone more in need of it than me.' Once he gave me some money and I said, 'Give it to someone more in need of it than me.' and the Prophet, may Allah bless him and grant him peace, said, "Take it, set it aside and then give it as sadaqa. Take what comes to you of this wealth even if you are not looking for it or asking for it. Otherwise, do not seek it yourself."'" Salim ibn 'Abdullah related that 'Abdullah ibn 'Umar said, "I heard 'Umar say, 'The Prophet, may Allah bless him and grant him peace, used to give me gifts and I would say, 'Give it to someone more in need of it than me' until once he gave me some money and I said, 'Give it to someone more in need of it than me.' and the Prophet, may Allah bless him and grant him peace, said, "Take it, set it aside, and then give it as sadaqa. Take what comes to you of this wealth even if you are not looking for it or asking for it. Otherwise, do not seek it yourself."'"