Muwatta Malik 78

Arabic

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 Abbas used to have nose-bleeds and would leave to wash off the blood. He would then return and complete his prayer

Authenticity

Da'if · Salim al-Hilali

Reference