صحيح ابن خزيمه
Sahih Ibn Khuzaymah
جماع أبواب الاستنجاء بالأحجارChapters on Cleaning with Stones
(59) بَابُ ذِكْرِ الدَّلِيلِ عَلَى أَنَّ الْأَمْرَ بِالِاسْتِطَابَةِ وِتْرًاChapter 59: Evidence that the command is to use an odd number
Hadith Q76
، هُوَ الْوِتْرُ الَّذِي يَزِيدُ عَلَى الْوَاحِدِ، الثَّلَاثُ فَمَا فَوْقَهُ مِنَ الْوِتْرِ، إِذِ الْوَاحِدُ قَدْ يَقَعُ عَلَيْهِ اسْمُ الْوِتْرِ، وَالِاسْتِطَابَةُ بِحَجَرٍ وَاحِدٍ غَيْرُ مُجْزِيَةٍ، إِذِ النَّبِيُّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ قَدْ أَمَرَ أَنْ لَا يُكْتَفَى بِدُونِ ثَلَاثَةِ أَحْجَارٍ فِي الِاسْتِطَابَةِ
The command to use an odd number of stones refers to an odd number that is more than one, such as three or more (for example, five, seven, etc.), because sometimes the term "odd" is also applied to one. However, using only one stone for istinja is not sufficient, because the Prophet (peace be upon him) commanded that less than three stones should not be considered sufficient for istinja.
