Sahih Muslim, 3101

Rapporté par Usama b. Zaid رضي الله عنه : Le Messager d’Allah ﷺ revenait de ‘Arafat et, en arrivant à un ravin, il est descendu et a uriné (Usama n’a pas dit qu’il avait versé de l’eau), mais il a précisé : Il (le Prophète) a demandé de l’eau et a fait une petite ablution. J’ai dit : Messager d’Allah, la prière ! Il a répondu : « La prière t’attend devant (à Muzdalifa). » Il a continué jusqu’à Muzdalifa et y a accompli les prières du coucher du soleil et de ‘Isha ensemble

Usama b. Zaid (Allah be pleased with him) narrated:AHah's Messenger (ﷺ) was on his way back from 'Arafat and as he reached the creek (of a hillock) he got down and urinated (Usama did not say that he poured water), but said: He (the Holy Prophet) called for water and performed ablution, but it was not a thorough one. I said: Messenger of Allah, the prayer! Thereupon he said: Prayer awaits you ahead (at Muzdalifa). He then proceeded, until he reached Muzdalifa and observed sunset and 'Isha' prayers (together) there