Hadith.3714 - Abu Al-Bakhtari Wahb ibn Wahb narrated from Imam Jafar ibn Muhammad Al-Sadiq (as) from his father, Imam Muhammad ibn Ali Al-Baqir (as) (peace be upon them), who said
Imam Ali ibn Abi Talib (as) ruled concerning a man who died and left heirs. One of the heirs acknowledged a debt against his father.
Imam Ali ibn Abi Talib (as) ruled that it would be binding upon him in his share, according to what he inherited, and it would not apply to the entire estate.
If two of the heirs acknowledged the debt and they were just (trustworthy), then it would be enforced against all the heirs. However, if they were not just, they would only be liable in their shares, based on what they inherited.
Similarly, if some of the heirs acknowledged a brother or sister, the acknowledgment would only apply to their share.
Imam Ali ibn Abi Talib (as) said: "Whoever acknowledges a brother, he is a partner in the wealth, but his lineage is not established.
If two heirs acknowledge him, the same applies-unless they are just (trustworthy), in which case his lineage is established, and he shares in the inheritance with them."