Sunan an-Nasa'i, Book 1, Hadith 134 (In-Book) ⓘ

It was narrated from Ibn Buraidah that his father said: "The Messenger of Allah used to perform Wudu' for every prayer. One the day of the Conquest (of Makkah), he offered all the prayers with one Wudu'. 'Umar said to him: 'You have done something that you never did before.' He said: 'I did that deliberately, O 'Umar.'"

أَخْبَرَنَا عُبَيْدُ اللَّهِ بْنُ سَعِيدٍ، قَالَ حَدَّثَنَا يَحْيَى، عَنْ سُفْيَانَ، قَالَ حَدَّثَنَا عَلْقَمَةُ بْنُ مَرْثَدٍ، عَنِ ابْنِ بُرَيْدَةَ، عَنْ أَبِيهِ، قَالَ كَانَ رَسُولُ اللَّهِ صلى الله عليه وسلم يَتَوَضَّأُ لِكُلِّ صَلاَةٍ فَلَمَّا كَانَ يَوْمُ الْفَتْحِ صَلَّى الصَّلَوَاتِ بِوُضُوءٍ وَاحِدٍ فَقَالَ لَهُ عُمَرُ فَعَلْتَ شَيْئًا لَمْ تَكُنْ تَفْعَلُهُ ‏.‏ قَالَ ‏ "‏ عَمْدًا فَعَلْتُهُ يَا عُمَرُ ‏" ‏ ‏.‏