حَدَّثَنَا سُوَيْدُ بْنُ سَعِيدٍ، حَدَّثَنَا شَرِيكٌ، عَنْ عَمْرِو بْنِ عَامِرٍ، عَنْ أَنَسِ بْنِ مَالِكٍ، قَالَ كَانَ رَسُولُ اللَّهِ ـ صلى الله عليه وسلم ـ يَتَوَضَّأُ لِكُلِّ صَلاَةٍ وَكُنَّا نَحْنُ نُصَلِّي الصَّلَوَاتِ كُلَّهَا بِوُضُوءٍ وَاحِدٍ ‏.‏

It was narrated that Anas bin Malik said: "The Messenger of Allah used to perform ablution for every prayer, and we used to perform all of the prayers with one ablution." Translation Not Available

Book Ref: Sunan Ibn Majah Book 1 Hadith 509
Web Ref:  Sunan Ibn Majah Vol 1 Book 1 Hadith 509