Musannaf Ibn Abi Shayba 13:2634

Abu Bakr narrated to us, he said: Ibn al-Mubarak narrated to us, from Uthman ibn Hakim, from Ata, from Ibn Abbas, who said: "Dates for dates on the tops of the palm trees [must be] by measure." He said: "If there is a dinar or ten dirhams between them, then there is no harm in it."