What is the ruling on a prayer performed while unaware of existing contamination, provided the contamination was actually present during the prayer?
Chapter on Praying with Impurity and Other Matters
Al-Mughni
Book of Prayer
Primary text
There are differing views. One view holds that the prayer is not invalidated. This opinion is supported by Ibn Umar, Atā', Sa'īd ibn al-Musayyab, Sālim, Mujāhid, al-Shā'bī, al-Nakha'ī, al-Zuhri, Yaḥyā al-Anṣārī, Isḥāq, and Ibn al-Mundhir. The basis for this view is the narration where the Prophet, peace be upon him, removed his sandals after being informed by Jibrīl that they contained filth, and the Companions followed suit without repeating their prayer. This suggests that ignorance of ritual impurity does not automatically invalidate the act, differentiating it from impurity of major ritual error (ḥadath) which is stricter.
Supporting text
A second view states that the prayer must be repeated. This is the position of Abū Qilābah and al-Shāfi'ī, who argue that purity is a required condition (ṭahāra mushtarata) for prayer and is not waived by ignorance, similar to impurity of ritual error. Rabī'ah and Mālik state that repetition is required if the time frame for the prayer has not elapsed, but not afterwards.