Sahih Bukhari Volume 2, Book 25, Hadith 1670

حَدَّثَنَا قُتَيْبَةُ، حَدَّثَنَا إِسْمَاعِيلُ بْنُ جَعْفَرٍ، عَنْ مُحَمَّدِ بْنِ أَبِي حَرْمَلَةَ، عَنْ كُرَيْبٍ، مَوْلَى ابْنِ عَبَّاسٍ عَنْ أُسَامَةَ بْنِ زَيْدٍ ـ رضى الله عنهما ـ أَنَّهُ قَالَ رَدِفْتُ رَسُولَ اللَّهِ صلى الله عليه وسلم مِنْ عَرَفَاتٍ فَلَمَّا بَلَغَ رَسُولُ اللَّهِ صلى الله عليه وسلم الشِّعْبَ الأَيْسَرَ الَّذِي دُونَ الْمُزْدَلِفَةِ أَنَاخَ، فَبَالَ ثُمَّ جَاءَ فَصَبَبْتُ عَلَيْهِ الْوَضُوءَ، فَتَوَضَّأَ وُضُوءًا خَفِيفًا‏.‏ فَقُلْتُ الصَّلاَةَ يَا رَسُولَ اللَّهِ‏.‏ قَالَ ‏"‏ الصَّلاَةُ أَمَامَكَ ‏"‏‏.‏ فَرَكِبَ رَسُولُ اللَّهِ صلى الله عليه وسلم حَتَّى أَتَى الْمُزْدَلِفَةَ، فَصَلَّى ثُمَّ رَدِفَ الْفَضْلُ رَسُولَ اللَّهِ صلى الله عليه وسلم غَدَاةَ جَمْعٍ‏

Narrated By Usama bin Zaid : Rode behind Allah's Apostle from 'Arafat and when Allah's Apostle reached the mountain pass on the left side which is before Al-Muzdalifa he made his camel kneel and then urinated, and then I poured water for his ablution. He performed light ablution and then I said to him: (Is it the time for) the prayer, O Allah's Apostle!" He replied, "The (place of) prayer is ahead of you (i.e. at Al-Muzdalifa)." So Allah's Apostle rode till he reached Al-Muzdalifa and then he offered the prayer (there). Then in the morning (10th Dhul-Hijja) Al-Fadl (bin Abbas) rode behind Allah's Apostle.