It is narrated from Sayyiduna Ali (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) used to say at the end of Witr: «اَللّٰهُمَّإِنِّيأَعُوذُبِرِضَاكَمِنْسَخَطِكَوَمُعَافَاتِكَمِنْعُقُوبَتِكَوَأَعُوذُبِكَمِنْكَلَاأُحْصِيثَنَاءًعَلَيْكَأَنْتَكَمَاأَثْنَيْتَعَلَىنَفْسِكَ» "O Allah! I seek refuge in Your pleasure from Your displeasure, in Your pardon from Your punishment, and I seek refuge in You from You. I cannot enumerate Your praises; You are as You have praised Yourself."
Hadith Referenceمسند احمد / مسند الخلفاء الراشدين / 1295