Hisham bin Hubairah (may Allah have mercy on him) said: "If someone makes a bequest for someone equal to one of his sons, then if his sons are male, he will receive the share of a male, and if they are female, he will receive the share of a female."
Hadith Referenceسنن سعید بن منصور / كتاب ولاية العصبة / 1527
Hadith Takhrij«أخرجه سعيد بن منصور فى «سننه» ترقيم الدرالسلفية برقم:، 350، وابن أبى شيبة فى «مصنفه» برقم: 31512»