Musannaf Ibn Abi Shayba 3:5766

'Abdah narrated to us, from Sa'id, from Shu'bah, from Yazid ibn Khumayr, who said: I heard Habib ibn 'Ubayd narrating from Jubayr ibn Nufayr, from Abu al-Samt, who said: I witnessed 'Umar at Dhu al-Hulayfah, as if he intended [to go to] Makkah. He prayed two rak'ahs. I said to him: "Why do you do this?" He said: "I am only doing as I saw the Messenger of Allah, may Allah bless him and grant him peace, doing."