Mukhtasar Bukhari

Narrated from Sayyiduna Abdullah bin Mas’ud that the Prophet (peace and blessings of Allah be upon him) offered prayer. Ibrahim is the narrator from Alqamah, and Alqamah is the narrator from Sayyiduna Ibn Mas’ud (may Allah be pleased with them), who says: I do not know whether the Prophet (peace and blessings of Allah be upon him) increased or decreased (something) in the prayer. Then, when the Prophet (peace and blessings of Allah be upon him) had finished the prayer with salam, it was said to him, “O Messenger of Allah! Has something new happened in the prayer?” The Prophet (peace and blessings of Allah be upon him) said, “What is that?” The people said, “You offered such and such amount of prayer.” So the Prophet (peace and blessings of Allah be upon him) drew his feet together, faced the qiblah, and performed two prostrations, then gave salam. Then, when he turned towards us, he said, “If any new command had been given regarding the prayer, I would have informed you (beforehand), but I am only a human being like you; just as you forget, I also forget. Therefore, when I forget, remind me, and when any one of you is uncertain in his prayer, he should try to determine what is correct and complete his prayer accordingly, then give salam and perform two prostrations (of forgetfulness).”