Musannaf Ibn Abi Shaybah 3054 — What is permitted to be said after

Umayr bin Sa'id said: Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) used to teach us the tashahhud in the prayer, then he would say: When one of you has finished the tashahhud, let him say these words: "O Allah, grant me the good that I know and the good that I do not know, and I seek protection from the evils that I know and from the evils that I do not know. O Allah, I ask You for all the good that Your righteous servants have asked of You. O Allah, I seek refuge with You from all the evils from which Your righteous servants have sought refuge. Our Lord, give us good in this world and good in the Hereafter, and protect us from the punishment of the Fire. Our Lord, we have believed, so forgive us our sins, overlook our misdeeds, and cause us to die among the righteous. Our Lord, grant us all that You promised us through Your Messengers, and do not disgrace us on the Day of Resurrection; indeed, You do not break Your promise."