Al-Kāfi - The Book of Wills

َّدُ بْنُ يَحْيَى عَنْ أَحْ٠َّدٍ عَنِ الْحَسَنِ [بْنِ إِبْرَاهِي٠َذَانِيِّ قَالَ كَتَبَ ٠َّدُ بْنُ يَحْيَى هَلْ لِلْوَصِيِّ أَنْ يَشْتَرِيَ شَيْئاً ٠َيِّتِ إِذَا بِيعَ فِي٠َنْ زَادَ فَيَزِيدَ وَيَأْخُذَ لِنَفْسِهِ فَقَالَ يَجُوزُ إِذَا اشْتَرَى صَحِيحاً. 10.

Muhammad ibn Yahya has narrated from Ahmad ibn Muhammad from al-Hassan [ibn Ibrahim] ibn Muhammad al-Hamadaniy who has narrated the following: “Once, Muhammad ibn Yahya wrote (to the Imam), ‘Is it lawful for an executor of the will to buy something from the assets of the deceased as the highest bidder? He (the Imam) said, ‘It is permissible if he buys it in an undamaged condition.’” جهول - Allamah Baqir al-Majlisi (Mirʾāt al-ʿUqūl fī Sharḥ Akhbār Āl al-Rasūl (3/96))