It wasnarrated that Umm Salamah said:
"The Messenger of Allah (ﷺ)usedto pray Witr with seven or five Rak'ah, and he would not saySalamor speak in between them." (DE)
English reference (DE): Vol. 1, Book 5, Hadith 1192 (DE)
Arabic reference (DE): Book 5, Hadith 1248 (DE)