Al-Kāfi - The Book of Wills

Chapter: The Will for a Part of One’s Assets 3- عَلِيُّ بْنُ إِبْرَاهِي٠َ عَنْ أَبِيهِ عَنْ حَ٠َّادٍ عَنْ أَبَانِ بْنِ تَغْلِبَ قَالَ قَالَ أَبُو جَعْفَرٍ (عَلَيْهِ السَّلا٠) الْجُزْءُ وَاحِدٌ ٠ِنْ عَشَرَةٍ لأنَّ الْجِبَالَ عَشَرَةٌ وَالطُّيُورَ أَرْبَعَةٌ. 3.

Ali ibn Ibrahim has narrated from his father from Hammad from Aban ibn Th’alabah who has narrated the following: “Abu Ja‘far (a.s.), has said, ‘A part is one-tenth because the mountains were ten and the birds were four.’” حسن - Allamah Baqir al-Majlisi (Mirʾāt al-ʿUqūl fī Sharḥ Akhbār Āl al-Rasūl (23/68))