The Messenger of Allah ﷺ taught me some words that I say during the witr. (The version of Ibn Jawwas has: I say them in the supplication of the witr.) They were: "O Allah, guide me among those Thou hast guided, grant me security among those Thou hast granted security, take me into Thy charge among those Thou hast taken into Thy charge, bless me in what Thou hast given, guard me from the evil of what Thou hast decreed, for Thou dost decree, and nothing is decreed for Thee. He whom Thou befriendest is not humbled. Blessed and Exalted art Thou, our Lord." (Using translation from Abū Dāʾūd 1425)
قِيلَ لِلْحَسَنِ بْنِ عَلِيٍّ ؓ أَيَّ شَيْءٍ حَفِظْتَ مِنْ رَسُولِ اللهِ ﷺ؟ قَالَ مَا حَفِظْتُ مِنْهُ إِلَّا كَلِمَاتٍ أَقُولُهُنَّ فِي الْوِتْرِ «اللهُمَّ اهْدِنِي فِيمَنْ هَدَيْتَ وَعَافِنِي فِيمَنْ عَافَيْتَ وَتَوَلَّنِي فِيمَنْ تَوَلَّيْتَ وَبَارِكْ لِي فِيمَا أَعْطَيْتَ وَقِنِي شَرَّ مَا قَضَيْتَ؛ إِنَّكَ تَقْضِي وَلَا يُقْضَى عَلَيْكَ تَبَارَكْتَ رَبَّنَا وَتَعَالَيْتَ»