Hadith 5:324
Abu Bakr narrated to us, he said: Ibn Idris narrated to us, from Layth, from Mujahid, from Ibn Mas’ud, that he used to say: "Calculate what is due as Zakat on the orphan's wealth. Then, when he reaches maturity and you perceive in him sound judgment, hand it over to him. If he wishes, he may pay Zakat [on it], and if he wishes, he may leave it."
حدثنا أبو بكر قال ثنا بن إدريس عن ليث عن مجاهد عن بن مسعود أنه كان يقول أحص ما يجب في مال اليتيم من الزكاة فإذا بلغ وأونس منه رشدا ( ( ( رشد ) ) ) فأدفعه إليه فإن شاء زكاة وإن شاء تركه