If someone doubts his call to prayer (adhan) after he has already begun the prayer, he should continue. If someone doubts the iqamah after he has said the Takbir, he should continue. If someone doubts the Takbir after he has recited, he should continue. If someone doubts the recitation after he has bowed (ruku'), he should continue. If someone doubts the bowing after he has prostrated (sujud), he should continue. If someone doubts anything after he has entered another stage of prayer, he should continue and not pay attention to the doubt unless he is certain. If someone is certain that he missed the adhan and the iqamah, but has not yet read the whole Surah, there is no harm in skipping the adhan. He should pray upon the Prophet صلى الله عليه وعلى آله وسلم and say, Qad qamat as-salah [The prayer has been established]. If someone is certain he has not made the Takbir al-Ihram (the opening Takbir), he should repeat the prayer. But how can he be certain?"