The Prophet ﷺ said, "Whoever is afflicted with something in his body and leaves it to Allah, it will be an expiation for him."
عن النبي ﷺ قال: من أصيب بشيء في جسده فتركه الله، كان كفارة له.
Ahmad (23494) narrated it from Yahya bin Saeed Qattan, from Mujalid, from Amir, from Muharrar bin Abu Hurairah, from a man among the companions of the Prophet ﷺ, and he related it.Haythami said in Majma (6/302), "Ahmad narrated it, and it contains Mujalid, whose memory became confused." This is as he said, and the majority of scholars have criticized him, though Bukhari held a favorable opinion of him, saying, "He is truthful," while others declared him daif.However, I found another chain for it, which is what Abu Bakr bin Abu Shayba narrated in his Musnad, as found in Matalib Aliyah (1908), and Abu Yaala (6869), both through the route of Sufyan bin Uyayna, from Imran bin Zabyan, from Adi bin Thabit, who said, a man broke another man's mouth in the time of Muawiya , and he offered him blood money, but he refused it, so they raised it until they gave him three times the blood money. He said, then a man among the companions of the Prophet ﷺ related that the Prophet ﷺ said, "Whoever gives up as charity blood owed to him, or less than that, it will be an atonement for his past sins, from the day his mother bore him until the day he gave it as charity." He said, so the man forgave him.Haythami said in Majma (6/302), "Abu Yaala narrated it, and its narrators are the narrators of the Sahih, except for Imran bin Zabyan, whom Ibn Hibban deemed reliable, though he has some weakness."I say, Imran bin Zabyan is the Hanafi, the Kufan. Yaqub bin Sufyan Fasawi deemed him reliable on one occasion, and on another occasion said, "There is no harm in him." Abu Hatim said, "His hadith is recorded." Ibn Hibban mentioned him among the reliable narrators, but also mentioned him in Majruhin, saying, "He was among those who erred, though his error was not so severe as to invalidate reliance on him, yet one should not rely on him for reports he narrated alone."Through these two chains together, the hadith rises to the level of hasan.With a similar meaning, it was narrated from Ubada bin Samit, who said, I heard the Messenger of Allah say, "There is no man who suffers a wound on his body and forgives it as charity, except that Allah will forgive him the equivalent of what he gave as charity." Ahmad (22701) narrated it from Surayj bin Numan, who said, Hushaym narrated to us, from Mughira, from Shaybi, that Ubada bin Samit said, and he related the hadith.Bayhaqi (8/56) also narrated it through the route of Abu Dawud Tayalisi (587), who said, Muhammad bin Aban narrated to us, from Alqama bin Marthad, from Shaybi, who said, Ubada bin Samit said, in the presence of Muawiya, I heard the Messenger of Allah say, "Whoever is afflicted in his body to the extent of half his blood money, and forgives it, half of his sins will be atoned for him. And if it is a third, or a quarter, then according to that proportion." A man then said, "By Allah, did you hear this from the Messenger of Allah?" Ubada said, "By Allah, I indeed heard it from the Messenger of Allah."Bayhaqi said, "It is disconnected," meaning that Shaybi, who is Amir bin Sharahbil, did not meet Ubada bin Samit. Alai confirmed that he transmitted without a direct link (mursal) from Amr, Talha, Ibn Masud, Ayesha, and Ubada bin Samit.With a similar meaning, it was also narrated from Abu Darda, who said, I heard the Messenger of Allah say, "There is no man who is afflicted with something in his body and gives it as charity, except that Allah raises him a degree because of it, and removes a sin from him because of it."Tirmidhi (1393) narrated it from Ahmad bin Muhammad, who said, Abdullah bin Mubarak narrated to us, who said, Yunus bin Abu Ishaq narrated to us, who said, Abu Sifr narrated to us, saying, a man from Quraysh broke the tooth of a man from the Ansar, and he sought redress against him from Muawiya. He said to Muawiya, "O Commander of the Faithful, this man has broken my tooth." Muawiya said, "We shall satisfy you." The other man pressed Muawiya persistently, wearing him down, but he could not satisfy him. So Muawiya said to him, "Deal with your companion yourself." Abu Darda was sitting there, and he said, "I heard the Messenger of Allah say," and he related the hadith. The Ansari man said, "Did you yourself hear this from the Messenger of Allah?" He said, "My ears heard it, and my heart retained it." He said, "Then I leave it for him." Muawiya said, "By no means, I will not disappoint you," and he ordered that he be given money.Tirmidhi said, "This is a strange (gharib) hadith, we do not know it except through this route, and I am not aware that Abu Sifr heard directly from Abu Darda. Abu Sifr's name is Saeed bin Ahmad, and it is also said, bin Muhammad Thawri." He said this following his teacher, Bukhari, who stated explicitly, as found in Ilal al-Kabir (2/962), "Abu Sifr did not hear from Abu Darda, and his name is Saeed bin Yahya, and it is also said, Saeed bin Ahmad Thawri."Among those who also stated that it was disconnected is Bayhaqi (8/56). Through this same route, Ibn Majah (2693) also narrated it, in abridged form.