Sunan Abi Dawud 958
سنن أبي داود#958SahihAbdullah bin 'Umar said:"A Sunnah of the prayer is that you should raise your right foot, and make your left foot lie (on the ground)
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 (827)
In-book reference: 2:569