Sunan Abi Dawud 890
سنن أبي داود#890SahihIbn ‘Abbas reported the prophet (ﷺ) as saying :I have been commanded, and sometimes the narrator said: Your prophet (ﷺ) was commanded to prostrate on seven limbs
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: 2:500