Sunan Abi Dawud 672
سنن أبي داود#672SahihNarrated Abdullah ibn Abbas: The Prophet (ﷺ) said: The best of you are those whose shoulders are soft in prayer
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 ArnautHasan Lighairihi
Zubair Ali ZaiIsnaad Hasan
In-book reference: 2:282