Musannaf Ibn Abi Shayba 22:366

Mu'awiyah ibn 'Amr narrated to us, from Za'idah, from 'Asim, from Zirr, from 'Abdullah, who said: "If you dispute regarding the Qur'an concerning a 'ya', then make it a 'ya'. And remember the Qur'an, for it is a reminder."