وَقَالَ أَمِيرُ اَلْمُؤْمِنِينَ عَلَيْهِ اَلسَّلاَمُ: «مَا كَانَ مِنْ إِمَامٍ تَقَدَّمَ فِي اَلصَّلاَةِ وَ هُوَ جُنُبٌ نَاسِياً أَوْ أَحْدَثَ حَدَثاً أَوْ رَعَفَ رُعَافاً أَوْ أَزَّ أَزّاً فِي بَطْنِهِ فَلْيَجْعَلْ ثَوْبَهُ عَلَى أَنْفِهِ ثُمَّ لْيَنْصَرِفْ وَ لْيَأْخُذْ بِيَدِ رَجُلٍ فَلْيُصَلِّ مَكَانَهُ ثُمَّ لْيَتَوَضَّأْ وَ لْيُتِمَّ مَا سَبَقَهُ بِهِ مِنَ اَلصَّلاَةِ وَ إِنْ كَانَ جُنُباً فَلْيَغْتَسِلْ وَ لْيُصَلِّ اَلصَّلاَةَ كُلَّهَا.
The Commander of the Faithful Imam Ali ibn Abi Talib (a.s) said: "If an Imam leading the prayer realizes during the prayer that he is in a state of janabah (major ritual impurity) due to forgetfulness, or if he experiences a minor impurity, nosebleed, or a disturbance in his stomach, he should place his garment over his nose and leave the prayer. He should take the hand of a man to lead the prayer in his place, then perform wudu' and complete what remains of his prayer. If he is in a state of janabah, he should perform ghusl (ritual purification bath) and then repeat the entire prayer."