I heard the Prophet ﷺ say, "The night prayer is to be performed two units at a time. When you fear the approach of dawn, pray one unit as witr. Indeed, Allah is One, and He loves the odd number."
حدثنا محمد بن عبيد حدثنا الأعمش عن عطية بن سعد
سمعت النبي ﷺ يقول صلاة الليل مثنى مثنى فإذا خفت الصبح فواحدة إن الله تعالى وتر يحب الوتر
Its isnad is daif, due to the weakness of Atiya bin Saad bin Junada. But the text of the hadith is in itself sahih, for it is actually two hadiths. The first is that the night prayer is performed two units at a time, which has already come up repeatedly with sahih chains, the most recent being 6355, see also 6421. The second is that Allah is one and loves oneness, which has already come up from another route with a sahih isnad at 5880.