He heard the Messenger of Allah ﷺ say, "There are three things I swear by, and I will tell you something else, so memorize it. No servant's wealth is ever decreased by giving charity..." The hadith continues.
أنه سمع رسول الله ﷺ يقول: ثلاثة أقسم عليهن وأحدتكم حديثا فاحفظوه قال: ما نقص مال عبد من صدقة… الحديث.
Tirmidhi (2326) narrated it from Muhammad bin Ismail, who said, "Abu Naeem narrated to us, Ubada bin Muslim narrated to us, Yunus bin Khabab narrated to us, from Saeed Tai, Abu Bakhtari," who said, "Abu Kabsha Anmari narrated to me," and he mentioned it.Tirmidhi said, "Hasan sahih." Its isnad is hasan because of Yunus bin Khabab, about whom criticism was made due to his poor beliefs, since he was extreme in his Shiism, yet he is hasan in hadith so long as what he narrates does not support his innovation.On this subject there is also what was narrated from Abdul-Rahman bin Awf, who said, the Messenger of Allah ﷺ said, "Three things, by Him in whose hand is the soul of Muhammad, I would swear an oath concerning them. Wealth is never diminished by charity, so give charity. And no servant forgives a wrong, seeking thereby the face of Allah, but Allah raises him in honor through it." Abu Saeed, the freedman of Banu Hashim, said, "but Allah increases him in honor through it on the Day of Resurrection." "And no servant opens the door of begging but Allah opens for him the door of poverty."Imam Ahmad (1674), Abu Yaala (849), and Bazzar, in Kashf Astar (929), narrated it from the hadith of Abu Awana, from Umar bin Abu Salama, from his father, who said, "The storyteller of the people of Palestine narrated to me," saying, "I heard Abdul-Rahman bin Awf saying," and he mentioned it.However Bazzar narrated it through the route of Yunus bin Khabab, from Abu Salama bin Abdul-Rahman bin Awf, from his father, differing from Umar bin Abu Salama, from his father, who said, "The storyteller of the people of Palestine narrated to me," and he mentioned it. Bazzar said, "The hadith of Abu Salama from the storyteller of the people of Palestine, from Abdul-Rahman, is more sahih." In it there is a man who is not named, namely the storyteller of the people of Palestine, and it is on this basis that Haythami criticized it in Majma al-Zawaid (3/105).As for Yunus bin Khabab, who is Asidi, their freedman, of Kufa, there is disagreement about him, and most scholars are inclined to weaken him, since he used to curse the companions in general, and Uthman in particular. Abu Dawud said, "He was a curser of the companions," and Juzjani said, "He was a liar and a fabricator." The rule regarding him and those like him is that when he narrates a hadith that does not support his doctrine, and his lying and error do not become apparent, then his hadith is hasan. Indeed Tirmidhi graded one of his hadiths as sahih.