The Prophet ﷺ used to say at the end of his witr prayer, "O Allah, I seek refuge in Your pleasure from Your displeasure, and in Your pardon from Your punishment, and I seek refuge in You from You. I cannot enumerate Your praise. You are as You have praised Yourself."
حدثنا يزيد أنبأنا حماد بن سلمة عن هشام بن عمرو عن عبد الرحمن بن الحارث بن هشام
أن النبي ﷺ كان يقول في آخر وتره اللهم إني أعوذ برضاك من سخطك وأعوذ بمعافاتك من عقوبتك وأعوذ بك منك لا أحصي ثناء عليك أنت كما أثنيت على نفسك
Its isnad is sahih. Hisham bin Amr Fazari is trustworthy, an old shaikh. Abdul-Rahman bin Harith bin Hisham bin Mughira Makhzumi is a trustworthy successor, born during the time of the Messenger of Allah, and he was raised as a stepson under Umar's care.The hadith was also narrated by the authors of the four Sunan collections, as noted in Al-Muntaqa 1214. It will also come later among the additions of Abdullah, 1294.