The Messenger of Allah ﷺ ruled that full siblings born of the same mother inherit from one another to the exclusion of half-siblings born of different mothers. A man inherits from his brother who shares both his father and mother, to the exclusion of his brothers who share only his father.
حدثنا يحيى بن حكيم حدثنا أبو بحر البكراوي حدثنا إسرائيل عن أبي إسحق عن الحارث
قضى رسول الله ﷺ أن أعيان بني الأم يتوارثون دون بني العلات يرث الرجل أخاه لأبيه وأمه دون إخوته لأبيه