The Messenger of Allah ﷺ came out from the privy and was presented to him. They (the people) asked: Should we bring you water for ablution? He replied: I have been commanded to perform ablution when I get up for prayer.  

أَنَّ رَسُولَ اللَّهِ ﷺ خَرَجَ مِنَ الْخَلاَءِ فَقُدِّمَ إِلَيْهِ طَعَامٌ فَقَالُوا أَلاَ نَأْتِيكَ بِوَضُوءٍ فَقَالَ إِنَّمَا أُمِرْتُ بِالْوُضُوءِ إِذَا قُمْتُ إِلَى الصَّلاَةِ