Reward of 1000 Fasts

Rasoolullah (SallAllahu Alayhi wa Sallam) said, "The fast on the day of Arafah (9th Zul-Hijjah) is equivalent to one thousand fasts." #Shu'ab al-Iman

Holy Prophet (SallAllahu Alayhi wa Sallam) said, "I have presumption from Allah that the fast of Arafah (9th Zul-Hijjah) removes the sins of the previous year and the next year." #Sahih Muslim