مُوَطَّأُ مَالِكٍ
Muwatta Malik 664
Fasting
حَدَّثَنِي يَحْيَى، عَنْ مَالِكٍ، عَنْ نَافِعٍ، عَنْ عَبْدِ اللَّهِ بْنِ عُمَرَ، أَنَّهُ كَانَ يَحْتَجِمُ وَهُوَ صَائِمٌ - قَالَ - ثُمَّ تَرَكَ ذَلِكَ بَعْدُ فَكَانَ إِذَا صَامَ لَمْ يَحْتَجِمْ حَتَّى يُفْطِرَ .
Yahya related to me from Malik from Nafi that Abdullah ibn Umar used to be cupped while he was fasting. Nafi said, "He later stopped doing that, and would not be cupped when he was fasting until he had broken the fast."
Arabic/English book reference: Book 18, Hadith 30