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  

[Machine] "Do you know what I am performing ablution with? It is from the leaves of a plant called aqit, which I have consumed. Verily, I heard the Messenger of Allah ﷺ saying, 'Perform ablution with the water that has been touched by fire.'"  

أَتَدْرِي مِمَّا أَتَوَضَّأُ؟ مِنْ أَثْوَارِ أَقِطٍ أَكَلْتُهَا إِنِّي سَمِعْتُ رَسُولَ اللهِ ﷺ يَقُولُ تَوَضَّئُوا مِمَّا مَسَّتِ النَّارُ  

[Machine] He informed him that he found Abu Hurairah performing ablution at the back of the mosque. Abu Hurairah said, "I am performing ablution with the remnants of a sheep that I had eaten because the Messenger of Allah ﷺ said, 'Perform ablution with what the fire has touched.'"  

أَخْبَرَهُ أَنَّهُ وَجَدَ أَبَا هُرَيْرَةَ يَتَوَضَّأُ عَلَى ظَهْرِ الْمَسْجِدِ فَقَالَ أَبُو هُرَيْرَةَ إِنَّمَا أَتَوَضَّأُ مِنْ أَثْوَارِ أَقِطٍ أَكَلْتُهَا لِأَنَّ رَسُولَ اللهِ ﷺ قَالَ تَوَضَّئُوا مِمَّا مَسَّتِ النَّارُ  

[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»