Sahih al-Bukhari, Hadith 2658 ⓘ
Narrated Abu Sa`id Al-Khudri: The Prophet said, "Isn't the witness of a woman equal to half of that of a man?" The women said, "Yes." He said, "This is because of the deficiency of a woman's mind."
حَدَّثَنَا ابْنُ أَبِي مَرْيَمَ، أَخْبَرَنَا مُحَمَّدُ بْنُ جَعْفَرٍ، قَالَ أَخْبَرَنِي زَيْدٌ، عَنْ عِيَاضِ بْنِ عَبْدِ اللَّهِ، عَنْ أَبِي سَعِيدٍ الْخُدْرِيِّ ـ رضى الله عنه ـ عَنِ النَّبِيِّ صلى الله عليه وسلم قَالَ " أَلَيْسَ شَهَادَةُ الْمَرْأَةِ مِثْلَ نِصْفِ شَهَادَةِ الرَّجُلِ ". قُلْنَا بَلَى. قَالَ " فَذَلِكَ مِنْ نُقْصَانِ عَقْلِهَا ".
also referenced under: Book 52, Hadith 22 (In-Book) & Volume 3, Book 48, Hadith 826 (USC-MSA)