أَخْبَرَنِي مُحَمَّدُ بْنُ عَبْدِ اللَّهِ بْنِ عَمَّارٍ الْمَوْصِلِيُّ، عَنِ الْمُعَافَى، عَنْ عِصَامِ بْنِ قُدَامَةَ، عَنْ مَالِكٍ، - وَهُوَ ابْنُ نُمَيْرٍ الْخُزَاعِيِّ - عَنْ أَبِيهِ، قَالَ رَأَيْتُ رَسُولَ اللَّهِ صلى الله عليه وسلم وَاضِعًا يَدَهُ الْيُمْنَى عَلَى فَخِذِهِ الْيُمْنَى فِي الصَّلاَةِ وَيُشِيرُ بِأُصْبُعِهِ ‏.‏

It was narrated from Malik bin Numair Al-Khuza'I that his father said: "I saw the Messenger of Allah (PBUH) putting his right hand on his right thigh when praying and pointing with his finger." Translation Not Available

Book Ref: Sunan An Nisai Book 13 Hadith 1271
Web Ref:  Sunan An Nisai Vol 2 Book 13 Hadith 1272