His father said: "When the Messenger of Allah ﷺ sat in the second or fourth rak'ah, he would place his hands on his knees and point with his finger." (Using translation from Nasāʾī 1161)  

«كَانَ رَسُولُ اللهِ ﷺ إِذَا جَلَسَ فِي الثِّنْتَيْنِ أَوْ فِي الْأَرْبَعِ يَضَعُ يَدَيْهِ عَلَى رُكْبَتَيْهِ ثُمَّ أَشَارَ بِإصْبُعِهِ»