Narrated Abu Huraira:Allah's Messenger (ﷺ) said, "No 'Adwa." Abu Huraira also said: The Prophet (ﷺ) said, "The cattle suffering from a disease should not be mixed up with healthy cattle (or said "Do not put a patient with a healthy person as a precaution.") Abu Huraira also said: Allah's Messenger (ﷺ) said, "No 'Adwa." A bedouin got up and said, "Don't you see how camels on the sand look like deer but when a mangy camel mixes with them, they all get infected with mange?" On that the Prophet (ﷺ) said, "Then who conveyed the (mange) disease to the first camel?

English translation · Sahih al-Bukhari