(7) Fasting
كتاب الصوم
(4c) Chapter: Keeping the Fast free from Imperfection - Section 3
(3) باب تنزيه الصوم - الفصل الثالث
Mishkat al-Masabih 2017 
Bukhari said without a complete isnad that Ibn ‘Umar used to have himself cupped whan he was fasting. Then he abandoned it and had himself cupped at night.
وَعَنِ الْبُخَارِيِّ تَعْلِيقًا قَالَ: كَانَ ابْنُ عُمَرَ يَحْتَجِمُ وَهُوَ صَائِمٌ ثُمَّ تَرَكَهُ فَكَانَ يَحْتَجِمُ بِاللَّيْلِ
 لم تتمّ دراسته  (الألباني)حكم :
Reference : Mishkat al-Masabih 2017
In-book reference : Book 7, Hadith 61