Sayyiduna Kharijah bin Hudhafah al-Adawi (may Allah be pleased with him) said: I heard the Messenger of Allah (peace and blessings be upon him); he (peace and blessings be upon him) said: "Allah, the Lord of Might, has commanded you with a prayer that is better for you than red camels, and it is for you between the Isha prayer and the break of dawn: witr, witr." He (peace and blessings be upon him) said it twice.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 4460