The Prophet ﷺ used to perform witr with a single rakah, and he would speak between the two rakahs and the single rakah.
أن النبي ﷺ كان يوتر بركعة، وكان يتكلم بين الركعتين والركعة.
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Ibn Abu Shayba narrated it in his Musannaf (6871) from Shababa bin Sawwar, who said, Ibn Abu Dhib narrated to us, from Zuhri, from Urwa, from Ayesha, and he related it. Its chain is hasan because of Shababa bin Sawwar Fazari, of whom Ahmad said, "Truthful in hadith," and Ali bin Madini said, "He was a truthful elder, except that he held the view of Irja," and Abu Hatim said, "Truthful, his hadith is written down but not relied upon as proof." Khatib relates in Tarikh Baghdad (9/298), from Jafar bin Abu Uthman, from Ibn Main, that he said, "Truthful."