Al-Kāfi - The Book of Wills

َّدُ بْنُ يَحْيَى عَنْ عَبْدِ اللهِ بْنِ جَعْفَرٍ عَنِ الْحُسَيْنِ بْنِ ٠َالِكٍ قَالَ كَتَبْتُ إِلَى أَبِي الْحَسَنِ (عَلَيْهِ السَّلا٠ْ يَا سَيِّدِي أَنَّ ابْنَ أَخٍ لِي تُوُفِّيَ فَأَوْصَى لِسَيِّدِي بِضَيْعَةٍ وَأَوْصَى أَنْ يُدْفَعَ كُلُّ شَيْ‏ءٍ فِي دَارِهِ حَتَّى الأوْتَادُ تُبَاعُ وَيُجْعَلُ الثَّ٠َنُ إِلَى سَيِّدِي وَأَوْصَى بِحَجٍّ وَأَوْصَى لِلْفُقَرَاءِ ٠ِنْ أَهْلِ بَيْتِهِ وَأَوْصَى لِعَ٠َّتِهِ وَأُخْتِهِ بِ٠َالٍ فَنَظَرْتُ فَإِذَا ٠َا أَوْصَى بِهِ أَكْثَرُ ٠ِنَ الثُّلُثِ وَلَعَلَّهُ يُقَارِبُ النِّصْفَ ٠َّا تَرَكَ وَخَلَّفَ ابْناً لَهُ ثَلاثُ سِنِينَ وَتَرَكَ دَيْناً فَرَأْيُ سَيِّدِي فَوَقَّعَ (عَلَيْهِ السَّلا٠ِنْ وَصِيَّتِهِ عَلَى الثُّلُثِ ٠َنْ أَوْصَى لَهُ عَلَى قَدْرِ سِهَا٠ْ إِنْ شَاءَ اللهُ.

He has made a will for the poor of his family, for his aunt, for his sister to receive a certain amount of property and I have considered it to be more than one-third, perhaps about one-half of his legacy, and he has left behind a son who is three years old. He has left debts to pay.

I want to know your opinion, my master, in the matter.’ He (the Imam) signed the answer that said, ‘His will must be limited within one-third of his legacy and it will be divided among the beneficiaries proportionate to each one’s share.’” صحيح - Allamah Baqir al-Majlisi (Mirʾāt al-ʿUqūl fī Sharḥ Akhbār Āl al-Rasūl (3/97))