The Messenger of Allah ﷺ said, "There is no contagion." Abu Hurairah also used to narrate that the Messenger of Allah ﷺ said, "A sick camel should not be brought near healthy ones."Abu Salama said, Abu Hurairah used to narrate both of these statements from the Messenger of Allah ﷺ. Then later Abu Hurairah went silent about his saying, "There is no contagion," and held firm only to, "A sick camel should not be brought near healthy ones."Harith bin Abu Dhubab, who was the cousin of Abu Hurairah, said to him, "Abu Hurairah, I used to hear you narrate to us along with this hadith another hadith that you have now gone silent about. You used to say, 'The Messenger of Allah ﷺ said, There is no contagion.'"But Abu Hurairah refused to acknowledge that and said only, "A sick camel should not be brought near healthy ones."Harith kept pressing him on the point until Abu Hurairah grew angry and spoke to him in Abyssinian. He said to Harith, "Do you know what I just said?"Harith replied, "No."Abu Hurairah said, "I said, I refuse."Abu Salama said, By my life, Abu Hurairah used to narrate to us that the Messenger of Allah ﷺ said, "There is no contagion." So I do not know whether Abu Hurairah forgot it or whether one of the two statements abrogated the other.In another narration, Abu Salama said, I never saw him forget any hadith other than this one.
أن رسول الله ﷺ قال: لا عدوى، ويحدث أن رسول الله ﷺ قال: لا يورد ممرض على مصح قال أبو سلمة: كان أبو هريرة يحدثهما كلتيهما عن رسول الله ﷺ ثم صمت أبو هريرة بعد ذلك عن قوله: لا عدوى، وأقام على أن لا يورد ممرض على مصح. قال: فقال الحارث بن أبي ذباب ( وهو ابن عم أبي هريرة) قد كنت أسمعك يا أبا هريرة تحدثنا مع هذا الحديث حديثا آخر قد سكت عنه، كنت تقول: قال رسول الله ﷺ: لا عدوى فأبى أبو هريرة أن يعرف ذلك، وقال: لا يورد ممرض على مصح فما رآه الحارث في ذلك حتى غضب أبو هريرة، فرطن بالحبشية، فقال للحارث: أتدري ماذا قلت؟ قال: لا قال أبو هريرة: قلت: أبيت. قال أبو سلمة: ولعمري لقد كان أبو هريرة يحدثنا أن رسول الله ﷺ قال: لا عدوى فلا أدري أنسي أبو هريرة أو نسخ أحد القولين الآخر؟ وفي رواية: قال أبو سلمة: فما رأيته نسي حديثا غيره
Muslim narrated it in "Salam" (2221) via Ibn Wahb, who said, "Yunus told me, from Ibn Shihab, that Abu Salama bin Abdul-Rahman bin Awf..." and he mentioned it. Bukhari narrated it in "Tibb" (5771, 5773, 5774) through other routes from Zuhri, with similar wording but shortened, and the other version is his as well.The way to reconcile the two hadiths is that what has been established from the Prophet ﷺ, that he said, "There is no contagion," should be understood as referring to what the people of pre-Islamic ignorance believed, namely that disease transmits itself on its own without the will of Allah. His statement, "A sick person's animal should not be brought to mix with a healthy one," should be understood as meaning that a person should not believe that whatever affliction befell him was caused by his contact with the sick person. That is why we were commanded to flee from the leper as one flees from a lion.Furthermore, his statement, "There is no contagion," has many sahih corroborating narrations, so it may be that Abu Hurairah retracted his narration of "There is no contagion," thinking that it contradicted his statement ﷺ, "A sick person's animal should not be brought to mix with a healthy one."