Going to extremes in sniffing water up into the nostrils and blowing it out
حَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ، حَدَّثَنَا زَيْدُ بْنُ الْحُبَابِ، وَدَاوُدُ بْنُ عَبْدِ اللَّهِ، قَالاَ حَدَّثَنَا مَالِكُ بْنُ أَنَسٍ، عَنِ ابْنِ شِهَابٍ، عَنْ أَبِي إِدْرِيسَ الْخَوْلاَنِيِّ، عَنْ أَبِي هُرَيْرَةَ، قَالَ قَالَ رَسُولُ اللَّهِ ـ صلى الله عليه وسلم ـ " مَنْ تَوَضَّأَ فَلْيَسْتَنْثِرْ وَمَنِ اسْتَجْمَرَ فَلْيُوتِرْ " .
It was narrated that Abu Hurairah said: "The Messenger of Allah (ﷺ) said: 'Whoever performs ablution, let him clean his nose, and whoever uses pebbles to clean himself after defecating, let him use an odd number.'"