The Apostle of Allah ﷺ came out of the privy after relieving himself, and food was brought to him and he took it, and did not touch water. In another narration transmitted by Sa'id b. al-Huwairith it is like this: It was said to the Messenger of Allah ﷺ You have not performed ablution. He said: I do not intend to say prayer that I should perform ablution.  

أَنَّهُ سَمِعَ ابْنَ عَبَّاسٍ يَقُولُ إِنَّ النَّبِيَّ ﷺ قَضَى حَاجَتَهُ مِنَ الْخَلاَءِ فَقُرِّبَ إِلَيْهِ طَعَامٌ فَأَكَلَ وَلَمْ يَمَسَّ مَاءً قَالَ وَزَادَنِي عَمْرُو بْنُ دِينَارٍ عَنْ سَعِيدِ بْنِ الْحُوَيْرِثِ أَنَّ النَّبِيَّ ﷺ قِيلَ لَهُ إِنَّكَ لَمْ تَوَضَّأْ قَالَ مَا أَرَدْتُ صَلاَةً فَأَتَوَضَّأَ وَزَعَمَ عَمْرٌو أَنَّهُ سَمِعَ مِنْ سَعِيدِ بْنِ الْحُوَيْرِثِ