[Machine] The Messenger of Allah ﷺ used to perform ablution for every prayer until the day of the conquest of Mecca, where he performed all prayers with a single ablution and wiped over his socks. Umar said to him, "I saw you do something you didn't used to do?" He replied, "I deliberately did it, O Umar." Abu Muhammad said, "The action of the Messenger of Allah ﷺ indicates that the meaning of Allah's saying, 'When you rise to prayer, wash your faces' (Surah Al-Maidah 5:6) applies to every person who is impure and this includes the statement of the Prophet ﷺ , 'There is no ablution except from impurity.' And Allah knows best."  

كَانَ رَسُولُ اللَّهِ ﷺ يَتَوَضَّأُ لِكُلِّ صَلَاةٍ حَتَّى كَانَ يَوْمُ فَتْحِ مَكَّةَ صَلَّى الصَّلَوَاتِ بِوُضُوءٍ وَاحِدٍ وَمَسَحَ عَلَى خُفَّيْهِ فَقَالَ لَهُ عُمَرُ رَأَيْتُكَ صَنَعْتَ شَيْئًا لَمْ تَكُنْ تَصْنَعُهُ؟ قَالَ «إِنِّي عَمْدًا صَنَعْتُ يَا عُمَرُ» قَالَ أَبُو مُحَمَّدٍ فَدَلَّ فِعْلُ رَسُولِ اللَّهِ ﷺ أَنَّ مَعْنَى قَوْلِ اللَّهِ تَعَالَى {إِذَا قُمْتُمْ إِلَى الصَّلَاةِ فَاغْسِلُوا وُجُوهَكُمْ} [المائدة 6] الْآيَةَ لِكُلِّ مُحْدِثٍ لَيْسَ لِلطَّاهِرِ ومنْهُ قوْلُ النَّبيِّ ﷺ «لَا وُضُوءَ إِلَّا مِنْ حَدَثٍ» وَاللَّهُ أَعْلَمُ  

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. (Using translation from Abū Dāʾūd 172)   

«صَلَّى رَسُولُ اللَّهِ ﷺ الصَّلَوَاتِ كُلَّهَا يَوْمَ فَتْحِ مَكَّةَ بِوَضُوءٍ وَاحِدٍ وَمَسَحَ عَلَى خُفَّيْهِ» فَقَالَ لَهُ عُمَرُ إِنِّي رَأَيْتُكَ الْيَوْمَ صَنَعْتَ شَيْئًا لَمْ تَكُنْ تَصْنَعُهُ قَبْلَ الْيَوْمِ قَالَ «عَمْدًا فَعَلْتُ يَا عُمَرُ»