Musannaf Ibn Abi Shayba 21:138

Abu Mu'awiyah narrated to us, from al-A'mash, from 'Umayr ibn Sa'id, who said: 'Abdullah used to supplicate with these supplications after the tashahhud: "O Allah, I ask You for all good, what I know of it and what I do not know. And I seek refuge in You from all evil, what I know of it and what I do not know. O Allah, I ask You for the best of what Your righteous servants have asked You for, and I seek refuge in You from the evil of what Your righteous servants have sought refuge from. Our Lord, give us in this world [that which is] good and in the Hereafter [that which is] good and protect us from the punishment of the Fire. Our Lord, indeed we have believed, so forgive us our sins and remove from us our misdeeds and cause us to die with the righteous. Our Lord, and grant us what You promised us through Your messengers and do not disgrace us on the Day of Resurrection. Indeed, You do not fail in [Your] promise."