Muslim bin Abu Bakar said:
"My father (Abu Bakar رضي الله عنه) used to say following every prayer:
«اللَّهُمَّ إِنِّي أَعُوذُ بِكَ مِنَ الْكُفْرِ وَالْفَقْرِ وَعَذَابِ الْقَبْرِ»
[Allahumma inni aozhu bika min al-kufri wal-faqri wa 'azab al-qabr – Oh Allah, I seek refuge with You from Kufr, poverty, and the torment of the grave]
and I used to say them (these words). My father said: 'O my son, from whom did you learn this?' I said: 'From you.'
He said: "The Messenger of Allah (ﷺ) used to say them following the prayer."
An Nasaai 1347 | Sahih
"My father (Abu Bakar رضي الله عنه) used to say following every prayer:
«اللَّهُمَّ إِنِّي أَعُوذُ بِكَ مِنَ الْكُفْرِ وَالْفَقْرِ وَعَذَابِ الْقَبْرِ»
[Allahumma inni aozhu bika min al-kufri wal-faqri wa 'azab al-qabr – Oh Allah, I seek refuge with You from Kufr, poverty, and the torment of the grave]
and I used to say them (these words). My father said: 'O my son, from whom did you learn this?' I said: 'From you.'
He said: "The Messenger of Allah (ﷺ) used to say them following the prayer."
An Nasaai 1347 | Sahih