It is narrated from Sayyiduna Abu Hurayrah (may Allah be pleased with him) that the Prophet (peace and blessings be upon him) went into the mosque. A man entered the mosque and prayed, then came to the Messenger of Allah (peace and blessings be upon him) and greeted him with salam. He (peace and blessings be upon him) returned the greeting and said: "Go back and pray again, for you have not prayed." The man went back and prayed, then came again to the Prophet (peace and blessings be upon him) and greeted him with salam, and he (peace and blessings be upon him) said to him: "'Wa alayka al-salam' (And upon you be peace). Go back and pray, for you have not prayed." This went on until he had done so three times. At last he said: By the One who sent you with the truth, I cannot pray better than this, so please teach me. He (peace and blessings be upon him) said: "When you stand for prayer, say the takbir, then recite whatever of the Qur'an is easy for you, then bow until you are at ease in bowing, then raise your head from bowing and stand up straight, then prostrate with composure, then raise your head from prostration and sit with composure, then do the same throughout your whole prayer."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 2360