Muslim b. Abu Bakra said

My father used to say at the end of the prayer, “O Allah, I seek refuge in Thee from infidelity, poverty and the punishment in the grave.” I used to say these words also, so he asked me, “From whom did you get this, sonny?” When I told him that I had got it from him, he said that Allah's Messenger ﷺ used to say these words at the end of the prayer. Nasa'i and Tirmidhi transmitted it, but the latter did not mention "at the end of the prayer." Ahmad transmitted the wording of the tradition, but he had, "at the end of every prayer."