Musannaf Ibn Abi Shayba 13:2562

Abu Bakr narrated to us, he said: Abu al-Ahwas narrated to us, from Abd al-Aziz ibn Rufay’, from ‘Ata’ and Ibn Abi Mulaykah, they both said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "Whoever sells a slave who possesses wealth, then his wealth belongs to the seller, unless the buyer stipulates [otherwise], saying: 'I bought him from you along with his wealth.'" And whoever sells date palms that have been pollinated, then their fruit belongs to the seller, unless the buyer stipulates [otherwise].