وَحَدَّثَنِي عَنْ مَالِكٍ، عَنْ نَافِعٍ، وَعَبْدِ اللَّهِ بْنِ دِينَارٍ، أَنَّهُمَا أَخْبَرَاهُ أَنَّ عَبْدَ اللَّهِ بْنَ عُمَرَ قَدِمَ الْكُوفَةَ عَلَى سَعْدِ بْنِ أَبِي وَقَّاصٍ وَهُوَ أَمِيرُهَا فَرَآهُ عَبْدُ اللَّهِ بْنُ عُمَرَ يَمْسَحُ عَلَى الْخُفَّيْنِ فَأَنْكَرَ ذَلِكَ عَلَيْهِ فَقَالَ لَهُ سَعْدٌ سَلْ أَبَاكَ إِذَا قَدِمْتَ عَلَيْهِ فَقَدِمَ عَبْدُ اللَّهِ فَنَسِيَ أَنْ يَسْأَلَ عُمَرَ عَنْ ذَلِكَ حَتَّى قَدِمَ سَعْدٌ فَقَالَ أَسَأَلْتَ أَبَاكَ فَقَالَ لاَ ‏.‏ فَسَأَلَهُ عَبْدُ اللَّهِ فَقَالَ عُمَرُ إِذَا أَدْخَلْتَ رِجْلَيْكَ فِي الْخُفَّيْنِ وَهُمَا طَاهِرَتَانِ فَامْسَحْ عَلَيْهِمَا ‏.‏ قَالَ عَبْدُ اللَّهِ وَإِنْ جَاءَ أَحَدُنَا مِنَ الْغَائِطِ فَقَالَ عُمَرُ نَعَمْ وَإِنْ جَاءَ أَحَدُكُمْ مِنَ الْغَائِطِ ‏.‏

Yahya related to me from Malik that Nafi and Abdullah ibn Dinartold him that Abdullah ibn Umar arrived at Kufa and went to Sad ibnAbi Waqqas, who was the Amir of Kufa at that time. Abdullah ibn Umarsaw him wiping over his leather socks and disapproved of it. So Sadsaid to him, "Ask your father when you get back." Abdullah returnedbut forgot to ask Umar about the matter until Sad arrived and said,"Have you asked your father?" and he said, "No." Abdullahthen asked Umar and Umar replied, "If your feet are ritually pure whenyou put them in the leather socks then you can wipe over the socks."Abdullah said ,"What about if we have just come from relievingourselves?" Umar said, "Yes, even if you have just come from relievingyourself." Translation Not Available

Book Ref: Muwatta Imam Malik Book 2 Hadith 73
Web Ref:  Muwatta Imam Malik Book 2 Hadith 43