Al-Kāfi - Volume 7 > Another Chapter on Invalidity of al-‘Awl (deficiency or excess) and the Ordained Shares are not more than Six
Hadith #3

3- مُحَمَّدُ بْنُ يَحْيَى عَنْ أَحْمَدَ بْنِ مُحَمَّدٍ عَنْ عَلِيِّ بْنِ الْحَكَمِ عَنِ الْعَلاءِ بْنِ رَزِينٍ عَنْ مُحَمَّدِ بْنِ مُسْلِمٍ عَنْ أَبِي جَعْفَرٍ (عَلَيْهِ السَّلام) قَالَ السِّهَامُ لا تَعُولُ.

3. Muhammad ibn Yahya has narrated from Ahmad ibn Muhammad from Ali ibn al-Hakam from al-‘Ala’ ibn Razin from Muhammad ibn Muslim who has narrated the following: “Abu Ja‘far, ‘Alayhi al-Salam, has said, ‘The ordained shares do not face deficiency.”’