Muwatta Malik, Book 2, Hadith 46 (USC-MSA) ⓘ
Yahya related to me from Malik from Hisham ibn Urwa that he saw his father wiping over his leather socks. He said, "When he wiped over his socks he would never do more than wipe the tops and he would not wipe the bottoms."
حَدَّثَنِي يَحْيَى، عَنْ مَالِكٍ، عَنْ هِشَامِ بْنِ عُرْوَةَ، أَنَّهُ رَأَى أَبَاهُ يَمْسَحُ عَلَى الْخُفَّيْنِ قَالَ وَكَانَ لاَ يَزِيدُ إِذَا مَسَحَ عَلَى الْخُفَّيْنِ عَلَى أَنْ يَمْسَحَ ظُهُورَهُمَا وَلاَ يَمْسَحُ بُطُونَهُمَا .
also referenced under: Book 2, Hadith 76 (In-Book)