Al-Kāfi - Volume 7 > Another Chapter on Invalidity of al-‘Awl (deficiency or excess) and the Ordained Shares are not more than Six
Hadith #7

7- أَبُو عَلِيٍّ الأشْعَرِيُّ عَنْ مُحَمَّدِ بْنِ عَبْدِ الْجَبَّارِ عَنْ صَفْوَانَ بْنِ يَحْيَى عَنْ خُزَيْمَةَ بْنِ يَقْطِينٍ عَنْ عَبْدِ الرَّحْمَنِ بْنِ الْحَجَّاجِ عَنْ بُكَيْرٍ عَنْ أَبِي عَبْدِ اللهِ (عَلَيْهِ السَّلام) قَالَ أَصْلُ الْفَرَائِضِ مِنْ سِتَّةِ أَسْهُمٍ لا تَزِيدُ عَلَى ذَلِكَ وَلا تَعُولُ عَلَيْهَا ثُمَّ الْمَالُ بَعْدَ ذَلِكَ لأهْلِ السِّهَامِ الَّذِينَ ذُكِرُوا فِي الْكِتَابِ.

7. Abu Ali al-Ash‘ariy has narrated from Muhammad ibn ‘Abd al-Jabbar from Safwan ibn Yahya from Khudhaymah ibn Yaqtin from ‘Abd al-Rahman ibn al-Hajjaj from Bukayr who has narrated the following: “Abu ‘Abd Allah, ‘Alayhi al-Salam, has said, ‘The roots of ordained shares are six. They do not increase or face deficiency and thereafter the legacy is for those whose shares are mentioned in the book (of Allah).”’