Musannaf Ibn Abi Shayba 13:2635

Abu Bakr narrated to us, he said: Ibn Numayr narrated to us, he said: Uthman ibn Hakim narrated to us, from Ata, from Ibn Abbas, he said: There is no harm in selling dates upon the tops of the palm trees for measured dates, if there is in it ten dirhams or a dinar.