Sunan Abi Dawud 889
سنن أبي داود#889SahihNarrated Abdullah ibn Abbas: Ibn Abbas reported the Prophet (ﷺ) as saying: I have been commanded - according to the version of Hammad: Your Prophet (ﷺ) was commanded - to prostrate on seven (bones), and not to fold back the hair or the clothing
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Al-AlbaniSahih
Muhammad Muhyi Al-Din Abdul HamidSahih
Shuaib Al ArnautSahih
Zubair Ali ZaiSahih Bukhari (815) Sahih Muslim (490)
In-book reference: 2:499