Abu Malik al-Ash'ari (may Allah be pleased with him) says: Shall I not describe to you the prayer of the Prophet (peace and blessings be upon him)? Then he said: When the iqamah for prayer was given, the men would form a row, and after them the boys would form a row; then he (peace and blessings be upon him) would lead them in prayer. When he (peace and blessings be upon him) prostrated and when he raised his head from prostration, he would say 'Allahu akbar' (Allah is the Greatest), and when he stood up after two rak'ahs he would say 'Allahu akbar' (Allah is the Greatest); then he would give salam to the right and to the left. Then he said: "This is how the prayer is." Abd al-A'la (may Allah have mercy on him) says: I think he said: This is the prayer of the Prophet (peace and blessings be upon him).
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 5165