صحيح مسلم Sahih Muslim كتاب الحج The Book of Pilgrimage
باب بَيَانِ أَنَّ حَصَى الْجِمَارِ سَبْعٌ:

Chapter: The number of pebbles for stoning the Jamrahs is seven at a time

1 hadith
Hadith 1300
وَحَدَّثَنِي سَلَمَةُ بْنُ شَبِيبٍ ، حَدَّثَنَا الْحَسَنُ بْنُ أَعْيَنَ ، حَدَّثَنَا مَعْقِلٌ وَهُوَ ابْنُ عُبَيْدِ اللَّهِ الْجَزَرِيُّ ، عَنْ أَبِي الزُّبَيْرِ ، عَنْ جَابِرٍ ، قَالَ : قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ : " الِاسْتِجْمَارُ تَوٌّ ، وَرَمْيُ الْجِمَارِ تَوٌّ ، وَالسَّعْيُ بَيْنَ الصَّفَا ، وَالْمَرْوَةِ تَوٌّ ، وَالطَّوَافُ تَوٌّ ، وَإِذَا اسْتَجْمَرَ أَحَدُكُمْ فَلْيَسْتَجْمِرْ بِتَوٍّ " .
Jabir (b. Abdullab) (RA) reported Allah's Messenger (ﷺ) as saying: Odd number of stones are to be used for cleaning (the private parts after answering the call of nature), and casting of pebbles at the Jamras is to be done by odd numbers (seven), and (the number) of circuits between al-Safa' and al-Marwah is also odd (seven), and the number of circuits (around the Ka’bah) is also odd (seven). Whenever any one of you is required to use stones (for cleaning the private parts) he should use odd number of stones (three, five or seven).
Hadith Reference Sahih Muslim / The Book of Pilgrimage / Hadith: 1300
Hadith Grading محدثین: أحاديث صحيح مسلم كلها صحيحة
Hadith Takhrij «أحاديث صحيح مسلم كلها صحيحة»