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
Sayyiduna Kharijah bin Hudhafah al-Adawi (may Allah be pleased with him) said: One day the Messenger of Allah (peace and blessings be upon him) came out to us at the time of the morning prayer. He (peace and blessings be upon him) said: "Allah has commanded you with a prayer. This prayer is better for you than red camels." We said: Which prayer is it? He (peace and blessings be upon him) said: "Witr, which is between Isha and the break of dawn."
Muhammad bin Isma'il al-Bukhari said: For its chain, it is not known that its narrators heard from one another.
The Shaykh (may Allah have mercy on him) said: Something similar has been narrated regarding the two rak'ahs of Fajr with a chain more authentic than this.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 4462
Sayyiduna Abu Sa'id al-Khudri (may Allah be pleased with him) said that the Prophet (peace and blessings be upon him) said: "Allah, the Lord of Might, has added one prayer to your prayers. This prayer is better for you than red camels. Listen! It is the two rak'ahs before the Fajr prayer."
Al-Abbas bin al-Walid said: Yahya bin Ma'in said to me: This hadith is gharib (singular) from the narration of Mu'awiyah bin Sallam. Mu'awiyah bin Sallam is the hadith scholar of the people of Sham and he is saduq (truthful) in hadith; whoever does not write down his hadith, both its connected and its broken narrations, is not a man of hadith.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 4463
Ibn Buraydah narrates from his father (may Allah be pleased with him) that the Prophet (peace and blessings be upon him) said: "Witr is a duty (haqq); whoever does not pray witr has no connection with us."
Al-Bukhari said: Ubaydullah bin Abdullah Abu al-Munib narrates from Ibn Buraydah, and Zayd bin al-Hubab heard from him; he has munkar (denounced) narrations. Abu Ahmad (Ibn Adi) said: In my view there is no harm in him, and Yahya bin Ma'in also declared him thiqah (trustworthy). And Allah knows best.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 4464
Abdullah bin Abi al-Safar (may Allah have mercy on him) narrates from al-Sha'bi (may Allah have mercy on him) that witr is voluntary, and it is the finest of the voluntary prayers.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 4465