The Messenger of Allah ﷺ used to teach them this supplication just as he would teach them a surah from the Quran. He would say, "O Allah, I seek refuge in You from the punishment of Hell, I seek refuge in You from the punishment of the grave, I seek refuge in You from the trial of the False Messiah Dajjal, and I seek refuge in You from the trials of life and death."
أن رسول الله ﷺ كان يعلمهم هذا الدعاء، كما يعلمهم السورة من القرآن، يقول: اللهم إني أعوذ بك من عذاب جهنم، وأعوذ بك من عذاب القبر، وأعوذ بك من فتنة المسيح الدجال، وأعوذ بك من فتنة المحيا والممات.
Malik narrated it in Kitab al-Quran (33), from Abu Zubayr Makki, from Tawus Yamani, from Abdullah bin Abbas, who mentioned it.Muslim narrated it in al-Masajid (590), from Qutayba, from Malik, with the same chain.