Hadith 10:147
Ibn ‘Abbas said that when God’s Messenger died he left nine wives, eight of whom he used to visit equally. (The next tradition explains this) (Bukhari and Muslim.)
عَنِ ابْنِ عَبَّاسٍ: أَنَّ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ قُبِضَ عَنْ تِسْعِ نِسْوَةٍ وَكَانَ يقسم مِنْهُنَّ لثمان
Original Reference: Mishkat al-Masabih 3229