The Prophet ﷺ said, "I must not find any one of you reclining on his couch, when a matter I have commanded or forbidden reaches him, saying, 'We do not know. Whatever we find in the Book of Allah, we follow.'"
عن النبي ﷺ قال: لا ألفين أحدكم متكئا على أريكته، يأتيه الأمر من أمري مما أمرت به، ونهيت عنه، فيقول: لاندري، ما وجدنا في كتاب الله اتبعناه.
Abu Dawud (4605) and Ahmad (23876) narrated it, and Hakim graded it sahih (1/108) through various routes from Sufyan (that is, Ibn Uyayna), from Abu Nadr Salim, from Ubaydullah bin Abu Rafi, from his father, from the Prophet ﷺ, and he related it.Hakim said, "Sufyan bin Uyayna established this chain, and it is sahih according to the criteria of the two Shaykhs."I say, Malik bin Anas also narrated it in the same way, from Salim Abu Nadr, and Ibn Hibban (13) narrated it through his route. Its chain is sahih. There has been considerable disagreement over its chain, which Daraqutni set out in Al-Ilal (1172), then said at the end, "The correct view is that of the one who said, from Abu Nadr, from Ibn Abu Rafi, from his father."