Abu Zabyan (may Allah have mercy on him) said: Sayyiduna Ali (may Allah be pleased with him) set off towards the market and I was behind him. He stopped on the steps and faced the dawn, then recited: "By the night as it departs,
and by the morning as it breathes" [Surah al-Takwir: 17, 18], then he said: "Where is the one who was asking about witr? This is an excellent time for witr."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 4523