Yazid bin Hurmuz (may Allah have mercy on him) says that Najdah wrote him (Ibn Abbas) a letter, which also asked when an orphan leaves the age of orphanhood and his right in the fay' becomes established. So Abdullah bin Abbas (may Allah be pleased with them both) wrote to him that on reaching puberty the orphan's orphanhood ends and his right in the fay' becomes established.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب السير / 17967