When the Messenger of Allah ﷺ sat during prayer, he would place his left foot between his thigh and his shin, spread out his right foot, place his left hand on his left knee, place his right hand on his right thigh, and point with his finger.In another narration, when the Messenger of Allah ﷺ sat to make supplication, he would place his right hand on his right thigh and his left hand on his left thigh, point with his index finger, place his thumb on his middle finger, and cup his left palm over his knee.
كان رسول الله ﷺ إذا قعد في الصلاة جعل قدمه اليسرى بين فخذه وساقه، وفرش قدمه اليمنى، ووضع يده اليسرى على ركبته اليسرى، ووضع يده اليمنى على فخذه اليمنى، وأشار بإصبعه. وفي رواية: كان رسول الله ﷺ إذا قعد يدعو وضع يده اليمنى على فخذه اليمنى، ويده اليسرى على فخذه اليسرى، وأشار بإصبعه السبابة، ووضع إبهامه على إصبعه الوسطى، ويلقم كفه اليسرى ركبته.
Muslim reported it in the Book of Mosques (579). The first narration is via Uthman bin Hakeem, who said, "Amir bin Abdullah bin Zubayr told me, from his father," and he related the same account. The second narration is via Ibn Ajlan, from Amir bin Abdullah bin Zubayr, from his father, and he related the same account.As for his statement "he spread his right foot flat," what is known from the sahih hadiths is that he kept his right foot upright, so perhaps he spread it flat on one occasion to show that this too is permissible. His statement "he placed his left foot between his thigh and shin" describes the position of tawarruk.As for the statement in the hadith of Ibn Umar, "he formed the number fifty-three," and in the hadith of Ibn Zubayr, "he pointed with his index finger and placed his thumb on his middle finger," Nawawi said, "These two narrations are to be understood as referring to two different occasions, he did this at one time and that at another." End of quote.