حَدَّثَنِي يَحْيَى، عَنْ مَالِكٍ، عَنْ نَافِعٍ، أَنَّ عَبْدَ اللَّهِ بْنَ عُمَرَ، كَانَ إِذَا سَجَدَ وَضَعَ كَفَّيْهِ عَلَى الَّذِي يَضَعُ عَلَيْهِ جَبْهَتَهُ ‏.‏ قَالَ نَافِعٌ وَلَقَدْ رَأَيْتُهُ فِي يَوْمٍ شَدِيدِ الْبَرْدِ وَإِنَّهُ لَيُخْرِجُ كَفَّيْهِ مِنْ تَحْتِ بُرْنُسٍ لَهُ حَتَّى يَضَعَهُمَا عَلَى الْحَصْبَاءِ ‏.‏

Yahya related to me from Malik from Nafi that Abdullah ibn Umarused to place his palms flat on the surface where he put his forehead.Nafi said, "I have seen him take his hands out from under his burnuson a very cold day and place them on the ground." Translation Not Available

Book Ref: Muwatta Imam Malik Book 9 Hadith 393
Web Ref:  Muwatta Imam Malik Book 9 Hadith 62