It is related from Isma'il bin Umayyah (may Allah have mercy on him), after the aforementioned report, (that he asked): When does an orphan come out of orphanhood, and when is his right in the fay' (wealth gained without fighting) established? He replied: "When he reaches puberty, the boy is no longer an orphan, and his right in the fay' is established."
Yazid bin Iyad is not used as evidence, and Sa'id bin Abi Sa'id has dropped out of its chain.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب السير / 17853