Sahih Ibn Khuzaymah

Narrated from Sayyiduna Abu Hurairah (may Allah be pleased with him) that the Messenger of Allah (peace and blessings of Allah be upon him) entered the mosque. (After him) a man came, he performed prayer (then came to the service of the Prophet, peace and blessings be upon him) and greeted him with salam. The Prophet (peace and blessings be upon him) replied to his salam, then said: "Go back and pray, for you have not prayed." (He prayed again and came back, but the Prophet, peace and blessings be upon him, repeated the same instruction) until the Prophet (peace and blessings be upon him) did this three times (sent him back and he prayed). Then the man said, "O Messenger of Allah, by Him Who has sent you with the truth, I do not know any way (of prayer) other than this (so please teach me the correct way)." The Prophet (peace and blessings be upon him) said: "When you stand for prayer (facing the qiblah), say « اللهُ أَكْبَرُ », then recite whatever portion of the Qur'an is easy for you, then bow with complete calmness and tranquility, then rise until you stand straight with moderation, then prostrate with complete calmness and tranquility, then when you raise your head from prostration, sit with complete calmness. And do this (maintain calmness and tranquility) throughout your prayer." Imam Abu Bakr (may Allah have mercy on him) said: This is the narration of Bundar.