I asked Anas b. Malik about ablution. He replied: The Prophet ﷺ performed ablution for each prayer and we offered (many) prayers with the same ablution.  

كَانَ النَّبِيُّ ﷺ يَتَوَضَّأُ لِكُلِّ صَلاَةٍ وَكُنَّا نُصَلِّي الصَّلَوَاتِ بِوُضُوءٍ وَاحِدٍ  

The Messenger of Allah ﷺ performed five prayers with the same ablution of the occasion of the capture of Mecca, and he wiped over his socks. ‘Umar said to him(the Prophet): I saw you doing a thing today that you never did. He said: I did it deliberately.  

صَلَّى رَسُولُ اللَّهِ ﷺ يَوْمَ الْفَتْحِ خَمْسَ صَلَوَاتٍ بِوُضُوءٍ وَاحِدٍ وَمَسَحَ عَلَى خُفَّيْهِ فَقَالَ لَهُ عُمَرُ إِنِّي رَأَيْتُكَ صَنَعْتَ الْيَوْمَ شَيْئًا لَمْ تَكُنْ تَصْنَعُهُ قَالَ عَمْدًا صَنَعْتُهُ