كتاب الطهارة
2  
Purity

Yahya related to me from Malik from Nafi that Abdullah ibn Umar would leave and do wudu if he had a nose-bleed and then return and complete his prayer without saying anything.

حَدَّثَنِي يَحْيَى، عَنْ مَالِكٍ، عَنْ نَافِعٍ، أَنَّ عَبْدَ اللَّهِ بْنَ عُمَرَ، كَانَ إِذَا رَعَفَ انْصَرَفَ فَتَوَضَّأَ ثُمَّ رَجَعَ فَبَنَى وَلَمْ يَتَكَلَّمْ ‏.‏
USC-MSA web (English) reference : Book 2, Hadith 48
Arabic reference : Book 2, Hadith 78