This view was likewise adopted by al-Shāfiʿī in his earlier opinion, as al-Bayhaqī notes, and it is supported by the practice of Ibn ʿUmar — may Allah be pleased with him. Al-Bayhaqī relates from Yazīd ibn Hārūn: Muḥammad ibn Muṭarrif informed us, from Zayd ibn Muslim, who said: “I saw Ibn ʿUmar praying in his cloak while there was blood on it. Nāfiʿ came, removed the cloak from him, placed another cloak on him, and he continued with his prayer.”

ʿAbd al-Razzāq also reports: Maʿmar informed us, from al-Zuhrī, from Sālim, that while Ibn ʿUmar was in prayer he noticed blood on his garment. He stepped aside, signalled to the people, and they brought him water; he washed it off, then completed the remainder of his prayer without repeating it.

I say: this is the view preferred by Shaykh al-Islām Ibn Taymiyyah, may Allah have mercy on him. In the chapter “Avoiding Impurity” of al-Ikhtiyārāt al-ʿIlmiyyah he writes: “Whoever prays with an impurity on him out of forgetfulness or ignorance is not required to repeat the prayer. A number of scholars have said the same, for when someone’s intent is to avoid what is forbidden, his act of worship is not invalidated if he does the forbidden thing by mistake or through forgetfulness.”

Ibn al-Qayyim says in Ighāthat al-Lahfān: “Among the issues in which the Prophet ﷺ was lenient, whereas the obsessive were strict, is the fatwā given by ʿAbd Allāh ibn ʿUmar, ʿAṭāʾ ibn Abī Rabāḥ, Saʿīd ibn al-Musayyib, Ṭāwūs, Sālim, Mujāhid, al-Shaʿbī, Ibrāhīm al-Nakhaʿī, al-Zuhrī, Yaḥyā ibn Saʿīd al-Anṣārī, al-Ḥakam, al-Awzāʿī, Mālik, Isḥāq ibn Rāhwayh, Abū Thawr, Imām Aḥmad in the sounder of the two reports from him, and others: that if a man discovers impurity on his body or garment after completing the prayer he does not…"