Sunan at-Tirmidhi (Jami-al-Tirmidhi), Chapter: Salah (Prayers)

that the Prophet turned in salutation after offering two raka'at. So, DhuI Yadayn (RA) submitted to him, 'Has the prayer been curtailed or have you forgotten Messenger of Allah?" The Prophet (SAW) asked, "Is Dhul Yadayn correct?" The people said, "Yes!" So, he stood up and offered the remaining two raka'at. Then, he ended with the salutation. Then he called the takbir and went into prostration as he used to make prostrations, or longer than that. Then he called the takbir and got up and then made the second prostration like he was used to do, or lengthier than that. [Ahmed 7205, Bukhari 714, Muslim 573, Abu Dawud 1008, Nisai 1221, Ibn e Majah 12141]