What is the ruling regarding declaring a person Muslim based on their prayer?
Chapter on Imamate and Congregational Prayer
Al-Mughni
Book of Prayer
Primary text
The companions rule that a person's Islam is established by their prayer, whether in the land of war (*Dār al-Ḥarb*) or the land of Islam (*Dār al-Islām*), and whether they pray in congregation or alone. If he subsequently adheres to Islam, there is no issue. If he does not adhere to it, he is an apostate subject to the rulings of apostates. If he dies before anything contradicting Islam emerges, he is a Muslim, and his Muslim heirs inherit from him, not the non-Muslim ones.
Supporting text
Abu Hanifa holds that if he prays in congregation or alone in a mosque, the ruling is as stated by us, but if he prays alone outside the mosque, his Islam is not established. Some Shafi'i scholars hold that his Islam is never established because prayer is a branch of Islam, and one does not become Muslim by performing a branch, like Hajj or fasting. Others argue that if he prays in the land of Islam, he is not a Muslim because he might intend to conceal his religion through prayer, but if he prays in the land of war, he is a Muslim as there is no suspicion attached to him. Our evidence is the Prophet's saying, 'I have been commanded to fight people until they say, 'La ilaha illa Allah,' so when they say it, their blood and wealth are protected from me, except by its due right,' and 'I was forbidden from killing those who pray.' He made prayer the boundary between Islam and disbelief, so whoever prays has entered the boundary of Islam. Regarding a slave, he said, 'When he prays, he is your brother.' Moreover, prayer is an act of worship specific to Muslims, so performing it constitutes Islam, like the two testimonies. As for Hajj, infidels used to perform it, and fasting is abstaining from things that break the fast, which might be done by someone not fasting.