He (sallallaahu 'alaihi wa sallam) used to say, "When one of you has finished the [last] tashahhud, he should seek refuge with Allaah from four things; [saying:
O Allaah! I truly seek refuge with You] from the punishment of Hellfire, and from the punishment of the grave, and from the trials of living and dying, and from the evil [trials] of the False Christ. [Then he should supplicate for himself with what occurs to him.]"257 - "He (sallallaahu 'alaihi wa sallam) would supplicate with it in his own tashahhud."258
Also, "he used to teach the Companions (radi Allaahu 'anhum) this the way he taught them Soorahs of the Qur'aan."259