Language:
كتاب الوضوء
4  
Ablutions (Wudu')
(6)
Chapter: The completion (or perfection) of ablution (one should wash all the parts perfectly)
(6)
باب إِسْبَاغِ الْوُضُوءِ
Sahih al-Bukhari 139

Narrated Usama bin Zaid:

Allah's Messenger (ﷺ) proceeded from `Arafat till when he reached the mountain pass, he dismounted, urinated and then performed ablution but not a perfect one. I said to him, ("Is it the time for) the prayer, O Allah's Messenger (ﷺ)?" He said, "The (place of) prayer is ahead of you." He rode till when he reached Al-Muzdalifa, he dismounted and performed ablution and a perfect one, The (call for) Iqama was pronounced and he led the Maghrib prayer. Then everybody made his camel kneel down at its place. Then the Iqama was pronounced for the `Isha' prayer which the Prophet (ﷺ) led and no prayer was offered in between the two . prayers (`Isha' and Maghrib).

حَدَّثَنَا عَبْدُ اللَّهِ بْنُ مَسْلَمَةَ، عَنْ مَالِكٍ، عَنْ مُوسَى بْنِ عُقْبَةَ، عَنْ كُرَيْبٍ، مَوْلَى ابْنِ عَبَّاسٍ عَنْ أُسَامَةَ بْنِ زَيْدٍ، أَنَّهُ سَمِعَهُ يَقُولُ دَفَعَ رَسُولُ اللَّهِ صلى الله عليه وسلم مِنْ عَرَفَةَ حَتَّى إِذَا كَانَ بِالشِّعْبِ نَزَلَ فَبَالَ، ثُمَّ تَوَضَّأَ وَلَمْ يُسْبِغِ الْوُضُوءَ‏.‏ فَقُلْتُ الصَّلاَةَ يَا رَسُولَ اللَّهِ‏.‏ فَقَالَ ‏ "‏ الصَّلاَةُ أَمَامَكَ ‏"‏‏.‏ فَرَكِبَ، فَلَمَّا جَاءَ الْمُزْدَلِفَةَ نَزَلَ فَتَوَضَّأَ، فَأَسْبَغَ الْوُضُوءَ، ثُمَّ أُقِيمَتِ الصَّلاَةُ فَصَلَّى الْمَغْرِبَ، ثُمَّ أَنَاخَ كُلُّ إِنْسَانٍ بَعِيرَهُ فِي مَنْزِلِهِ، ثُمَّ أُقِيمَتِ الْعِشَاءُ فَصَلَّى وَلَمْ يُصَلِّ بَيْنَهُمَا‏.‏
Reference : Sahih al-Bukhari 139
In-book reference : Book 4, Hadith 5
USC-MSA web (English) reference : Vol. 1, Book 4, Hadith 141
  (deprecated numbering scheme)