Hadith Q28

وَالدَّلِيلُ عَلَى أَنَّ النَّبِيَّ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ إِنَّمَا أَعْلَمَ أَنْ لَا وُضُوءَ إِلَّا مِنْ صَوْتٍ أَوْ رِيحٍ عِنْدَ مَسْأَلَةٍ سُئِلَ عَنْهَا فِي الرَّجُلِ يُخَيَّلُ إِلَيْهِ أَنَّهُ قَدْ خَرَجَتْ مِنْهُ رِيحٌ فَيَشُكُّ فِي خُرُوجِ الرِّيحِ، وَكَانَتْ هَذِهِ الْمَقَالَةُ عَنْهُ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ: «لَا وُضُوءَ إِلَّا مِنْ صَوْتٍ أَوْ رِيحٍ» جَوَابًا عَمَّا عَنْهُ سُئِلَ فَقَطْ لَا ابْتِدَاءَ كَلَامٍ مُسْقَطًا بِهَذِهِ الْمَسْأَلَةِ إِيجَابَ الْوُضُوءِ مِنْ غَيْرِ الرِّيحِ الَّتِي لَهَا صَوْتٌ أَوْ رَائِحَةٌ، إِذْ لَوْ كَانَ هَذَا الْقَوْلُ مِنْهُ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ ابْتِدَاءً مِنْ غَيْرِ أَنْ تَقَدَّمَتْهُ مَسْأَلَةٌ كَانَتْ هَذِهِ الْمَقَالَةُ تَنْفِي إِيجَابَ الْوُضُوءِ مِنَ الْبَوْلِ وَالنَّوْمِ وَالْمَذْيِ، إِذْ قَدْ يَكُونُ الْبَوْلُ لَا صَوْتٌ لَهُ وَلَا رِيحٌ، وَكَذَلِكَ النَّوْمُ وَالْمَذْيُ لَا صَوْتَ لَهُمَا وَلَا رِيحَ، وَكَذَلِكَ الْوَدْيُ
And the explanation of the evidence that the statement of the Prophet (peace be upon him), "Wudu is only obligatory upon hearing a sound or perceiving a smell," was in response to the question that was asked to him: if a person thinks that something has come out from his stomach and he becomes doubtful about the emission of wind. The statement of the Prophet (peace be upon him) was only the answer to this question. His statement was not an independent discourse that would abolish the obligation of wudu without sound or smell. Because if this statement of the Prophet (peace be upon him) was independent and not in response to a question, then it would negate the obligation of wudu due to urine, sleep, and madhiy, because sometimes urine has neither sound nor smell, and similarly, sleep, madhiy, and wadi have neither sound nor smell.
Hadith Reference صحيح ابن خزيمه / جماع أبواب الأحداث الموجبة للوضوء / Q28