Narrated by Sayyiduna Amr bin Kharijah Khushani رضي الله عنه: The Noble Prophet صلى الله عليه وآله وسلم delivered a sermon to us while he صلى الله عليه وآله وسلم was mounted on his riding animal, and his animal was chewing the cud and its saliva was flowing onto my shoulders. He صلى الله عليه وآله وسلم said: Allah Almighty has fixed the share of every person in inheritance, therefore it is not permissible to make a bequest in favor of an heir.
Hadith Takhrij«صحيح لغيره۔ أخرجه ابن ماجه: 2712، والنسائي: 2/274، (انظر مسند أحمد ترقيم الرسالة: 18086 ترقیم بيت الأفكار الدولية: 18254»
Brief Explanation
Benefits: … The bequest of one third of the wealth pertains to that person who is not becoming an heir; the deceased is not permitted to make a bequest in favor of any heir for more than his prescribed Islamic share. If he does so, his bequest will be rejected.