Muslim

Hadith Commentary: Benefits and Issues: The Prophet (sallallahu alayhi wa sallam) would keep his hands so far apart from his armpits that a small goat could pass underneath.

1110. Commentary:

➊ The hands should be kept well away from the sides, and likewise, the abdomen should be raised away from the thighs.

➋ This posture is closer to humility, submissiveness, and modesty.

➌ The excellence of the Mothers of the Believers is evident in that they closely observed and understood the manner of worship of the Prophet sallallahu alayhi wa sallam, and then conveyed it to the Ummah in such a clear manner that no ambiguity remained... radi Allahu anhunna...

1148. Commentary: This hadith proves that sitting on the left thigh during prayer is Sunnah. This ruling is general and includes all sittings (jalsat) of the prayer, except for the sitting that has been excluded with evidence, such as the final tashahhud. Its exception is established from another narration, in which tawarruk is Sunnah—that is, to pass the left foot under the right shin and sit on the left buttock. The Imam’s (rahimahullah) reasoning from this hadith is clear: that one should sit on the left thigh between the two prostrations (sajdahs), because this sitting is also among those sittings regarding which no specific narration has been reported, except for this narration. Therefore, acting upon this narration, one should sit on the left thigh between the two prostrations.

In a narration of Sahih Muslim (536), sitting on the heels is considered Sunnah, and the scholars (ulama) have understood from this that it refers to sitting between the two prostrations. In this regard, that narration is contrary to this narration. The reconciliation between them is that both ways of sitting between the two prostrations are correct, but the first method is superior, because this was the frequent practice of the Prophet (sallallahu alayhi wa sallam). Unlike the final tashahhud, in which both ways are not correct; rather, only tawarruk is Sunnah, because this was the practice of the Prophet (sallallahu alayhi wa sallam). And Allah knows best. See also hadith numbers: 1106, 1107.

Benefit:
At the time of prostration (sujud), the arms should be kept separate from the sides, and the stomach should be kept apart from the thighs.

Benefit:
In this hadith, the manner of performing prostration (sajdah) is described: in prostration, the abdomen should be kept so far apart from the thighs that if a young goat were to pass underneath, it could do so. There is no difference between the way men and women perform prostration.