"The Messenger of allah stopped in the mountain pass where the rulers stop now, and urinated, then he performed a light Wudu and I said: 'O Messenger of Allah (isit time for ) prayer?' He said: 'The prayer is still ahead of you.' When we came to Al-Muzdalifah the people did not unload their camles until he had prayed."
Sunan an-Nasa'i Book 24, Hadith 408