Tirmidhi

Commentary:
1:
That is, this narration is from Amir himself, not from his father Sa’d radi Allahu anhu; therefore, this is a mursal narration.

2:
By “both hands” is meant both palms, and by placing them on the ground is meant placing them opposite the shoulders or the face. By keeping both feet standing is meant keeping them upright on the balls of their toes, and facing the qiblah with the tips of the toes.

3:
The summary of both these narrations is that Mu’alla bin Asad narrated this hadith from both Wahib and Hammad bin Mas’adah, and both of them narrated from Muhammad bin ‘Ajlan, and Muhammad bin ‘Ajlan from Muhammad bin Ibrahim, and Muhammad bin Ibrahim from Amir bin Sa’d. However, Wahib made it musnad and added the intermediary of Amir bin Sa’d’s father, Sa’d bin Abi Waqqas, after Amir bin Sa’d, whereas Hammad bin Mas’adah narrated it mursal, without the intermediary of Sa’d bin Abi Waqqas. The mursal narration of Hammad bin Mas’adah is more authentic than the musnad narration of Wahib, because several other people have also narrated it mursal just as Hammad bin Mas’adah did.

Note:
(Supported by the above hadith, this narration is hasan li ghayrihi.)