Imam Malik's Muwatta, Chapter: Prayer

Yahya related to me from Malik from Ayyub ibn Abi Tamima as-Sakhtayani from Muhammad ibn Sirin from Abu Hurayra that the Messenger of Allah, may Allah bless him and grant him peace, finished the prayer after two rakas and Dhu'l-Yadayn said to him, "Has the prayer been shortened or have you forgotten, Messenger of Allah?" The Messenger of Allah, may Allah bless him and grant him peace, said, "Has Dhu'l-Yadayn spoken the truth?" The people said, "Yes," and the Messenger of Allah, may Allah bless him and grant him peace, stood and prayed the other two rakas and then said, "Peace be upon you." Then he said, "Allah is greater" and went into a sadja as long as his usual prostrations or longer. Then he came up and said, "Allah is greater" and went into a sajda as long as his usual prostrations or longer and then came up.