It is narrated from Sayyiduna Jabir (may Allah be pleased with him) that the Prophet (peace and blessings be upon him) said: By the ten nights in Surah Al-Fajr is meant the first ten days of Dhul-Hijjah; by "Witr" is meant the Day of Arafah, and by "Shaf‘" is meant the tenth of Dhul-Hijjah.