Muwatta Malik
Book 2, Hadith 49
Arabic hadith text
وَحَدَّثَنِي عَنْ مَالِكٍ، أَنَّهُ بَلَغَهُ أَنَّ عَبْدَ اللَّهِ بْنَ عَبَّاسٍ، كَانَ يَرْعُفُ فَيَخْرُجُ فَيَغْسِلُ الدَّمَ عَنْهُ ثُمَّ يَرْجِعُ فَيَبْنِي عَلَى مَا قَدْ صَلَّى .
Translation
Yahya related to me from Malik from Nafi that Abdullah ibn Abbasused to have nose-bleeds and would leave to wash off the blood. Hewould then return and complete his prayer.