I am performing ablution because of having eaten pieces of cheese, for I heard the Messenger of Allah ﷺ say: Perform ablution (after eating anything) touched by fire.  

أَخْبَرَهُ أَنَّهُ وَجَدَ أَبَا هُرَيْرَةَ يَتَوَضَّأُ عَلَى الْمَسْجِدِ فَقَالَ إِنَّمَا أَتَوَضَّأُ مِنْ أَثْوَارِ أَقِطٍ أَكَلْتُهَا لأَنِّي سَمِعْتُ رَسُولَ اللَّهِ ﷺ يَقُولُ تَوَضَّئُوا مِمَّا مَسَّتِ النَّارُ  

"I saw Abu Hurairah performing Wudu' on the roof of the Masjid ans he said: 'I ate some tough cheese, so I performed Wudu' because of that. I heard the Messenger of Allah ﷺ commanding us to do Wudu' from that which has been touched by fire.'"  

رَأَيْتُ أَبَا هُرَيْرَةَ يَتَوَضَّأُ عَلَى ظَهْرِ الْمَسْجِدِ فَقَالَ أَكَلْتُ أَثْوَارَ أَقِطٍ فَتَوَضَّأْتُ مِنْهَا إِنِّي سَمِعْتُ رَسُولَ اللَّهِ ﷺ يَأْمُرُ بِالْوُضُوءِ مِمَّا مَسَّتِ النَّارُ  

"Perform Wudu' from that which has been heated with fire." (Using translation from Nasāʾī 178)   

أَنَّ النَّبِيَّ ﷺ قَالَ تَوَضَّئُوا مِمَّا مَسَّتِ النَّارُ  

"The Messenger of Allah said: 'Perform ablution after (eating) that which has been changed by fire.'" (Using translation from Ibn Mājah 486)   

قَالَ رَسُولُ اللهِ ﷺ تَوَضَّئُوا مِمَّا مَسَّتِ النَّارُ وَلَوْ مِنْ تَوْرِ أَقِطٍ  

[Machine] Abu Hurayrah ate a rib of a sheep, then he performed ablution (wudu). Afterwards, he said, "Do you know why I performed ablution? I ate a rib of a sheep. I heard the Messenger of Allah ﷺ say, 'Perform ablution from whatever has touched the fire.'"  

أَنَّ أَبَا هُرَيْرَةَ أَكَلَ أَثْوَارَ أَقِطٍ فَتَوَضَّأَ ثُمَّ قَالَ أَتَدْرُونَ لِمَ تَوَضَّأْتُ؟ إِنِّي أَكَلْتُ أَثْوَارَ أَقِطٍ سَمِعْتُ رَسُولَ اللَّهِ ﷺ يَقُولُ «تَوَضَّأْ مِمَّا مَسَّتِ النَّارُ»