Sahih Muslim #3102 · The Book of Pilgrimage

We came to a valley where people generally halted their (camels) for the sunset prayer. Allah's Messenger (ﷺ) halted his camel and urinated (and he did not say that he had poured water). He then called for water and performed light ablution. I said: Messenger of Allah, the prayer! Thereupon he said: Prayer awaits you (at Muzdalifa). and he rode on until we came to Muzdalifa. Then he offered the sunset prayer. and the people halted their camels at their places, and did not untie them until Iqama was pronounced for the 'Isha' prayer and he observed the prayer, and then they untied (their camels). I said: What did you do in the morning? He said: Al-Fadl b. Abbas (Allah be pleased with them) sat behind him (the Holy Prophet) in the morning, whereas I proceeded on foot with the Quraish who had gone ahead.