Mishkat al-Masabih 27 Fitan كتاب الفتن 120

وَعَنِ ابْنِ عُمَرَ رَضِيَ اللَّهُ عَنْهُمَا قَالَ: لَقِيتُهُ وَقَدْ نَفَرَتْ عَيْنُهُ فَقُلْتُ: مَتَى فَعَلَتْ عَيْنُكَ مَا أَرَى؟ قَالَ: لَا أَدْرِي. قُلْتُ: لَا تَدْرِي وَهِيَ فِي رَأْسِكَ؟ قَالَ: إِنْ شَاءَ اللَّهُ خَلَقَهَا فِي عَصَاكَ. قَالَ: فَنَخَرَ كأشد نخير حمَار سَمِعت. رَوَاهُ مُسلم

Ibn `Umar said: I met him when his eye was inflamed and asked him when his eye had become infected with the trouble I noticed. On his replying that he did not know I said, “You do not know, and yet it is in your head?” He replied, “If God will He will create it when you are unaware.” He then snorted as loudly as I have ever heard an ass snort. Muslim transmitted it.