من لا يحضره الفقيه, volume 4, page 185

Hadith.5421 - Al-Sakuni narrated from Imam Jafar ibn Muhammad Al-Sadiq (as) from his father, Imam Muhammad ibn Ali Al-Baqir (as), who said that the Commander of the Faithful (as) said: "Bequeathing one-fifth (khums) is recommended because Allah (swt), the Mighty and Majestic, has chosen one-fifth for Himself." Imam (as) also said: "One-fifth is moderation, one-fourth is exertion, and one-third is injustice."

Translation: Bab Ul Qaim Publications — attributed by Thaqalayn·The Arabic above is the original.

Hadith.5422 - Hammad ibn ʿIsa narrated from Shuayb ibn Yaʿqub from Abu Baṣir, who said: I asked Abu Abdullah (as) about a man who dies - how much of his wealth he can bequeath. Imam (as) said: "One-third of his wealth, and the same applies to a woman as well."

Translation: Bab Ul Qaim Publications — attributed by Thaqalayn·The Arabic above is the original.

Hadith.5423 - Aṣim ibn Humayd narrated from Muhammad ibn Qays from Abu Jafar mam Muhammad ibn Ali Al-Baqir (as), who said: "The Commander of the Faithful Imam Ali ibn Abi Talib (as) used to say: 'To bequeath one-fifth of my wealth is more beloved to me than to bequeath one-fourth, and to bequeath one-fourth is more beloved to me than to bequeath one-third. Whoever bequeaths one-third without leaving anything behind has gone to excess.'" Imam (as) also said: "Whoever bequeaths one-third of his wealth without leaving anything has reached the limit."

Translation: Bab Ul Qaim Publications — attributed by Thaqalayn·The Arabic above is the original.

Hadith.5424 - In the narration of Al-Hasan ibn Ali Al-Washsha' from Hammad ibn Uthman from Abu Abdullah Imam Jafar ibn Muhammad Al-Sadiq (as), that he said: "Whoever bequeaths one-third has harmed the heirs. Bequeathing one-fifth or one-fourth is better than bequeathing one-third." Imam (as) also said: "Whoever bequeaths one-third without leaving anything behind has gone to excess."

Translation: Bab Ul Qaim Publications — attributed by Thaqalayn·The Arabic above is the original.