Musannaf Ibn Abi Shayba 33:779

Ali ibn Mushir narrated to us, from Ibn Jurayj, from Ata, from Ubayd ibn Umayr, who said: Indeed, Allah has made lawful and made unlawful. So, what He has made lawful, deem it lawful; and what He has made unlawful, avoid it. And He left between that things which He did not make lawful and did not make unlawful. That is a pardon from Allah, which He has pardoned. Then he recited: "O you who have believed, do not ask about things..." until the end of the verse.