Mishkat al-Masabih 4 Prayer كتاب الصلاة 682

وَعَن خَارِجَة بن حذافة قَالَ: خَرَجَ عَلَيْنَا رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ وَقَالَ: ” إِنَّ اللَّهَ أَمَدَّكُمْ بِصَلَاةٍ هِيَ خَيْرٌ لَكُمْ مِنْ حُمْرِ النِّعَمِ: الْوَتْرُ جَعَلَهُ اللَّهُ لَكُمْ فِيمَا بَيْنَ صَلَاةِ الْعِشَاءِ إِلَى أَنْ يَطْلُعَ الْفَجْرُ ” . رَوَاهُ التِّرْمِذِيُّ وَأَبُو دَاوُد

Kharija b. Hudhafa told of God’s Messenger coming out to them and saying, “God has given you an extra prayer which is better for you than the high-bred camels,* the witr , which God has appointed for you between the evening prayer and the daybreak.” * Literally “the red ones of the camels.” These were considered to be the best quality. Tirmidhi and Abu Dawud transmitted it.