Muwatta Malik 390

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 Umar used 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 burnus on a very cold day and place them on the ground

Reference

Muwatta Malik 390

In-book

Book 9, Hadith 65