Virtue: The Prophet (pbuh) also said:
"There is no day on which Allah frees people from the Fire more so than on the day of 'Arafah. He comes close to those (people standing on 'Arafah), and then He reveals before His Angels saying, ‘What are these people seeking." (Muslim)
Things to Do on the Day of Arafah:
1. Fasting on the Day of Arafah: Fasting is highly encouraged and recommended for those not going on hajj. "Fasting on the Day of Arafah expiates the sins of the past year and the coming year." (Muslim)
2. Dua on the Day of Arafah: Say this very often: The Prophet Muhammad, peace be upon him, said: "The most excellent dua is the dua on the Day of Arafah, and the best of what I and the prophets before me have said, is "There is nothing that deserves to be worshiped in truth except Allaah, He is Alone and has no partner, to Him belongs the dominion and to Him belongs all praise, and He is All-Powerful over all things.'" 
Reference: Surah Al-Fajr 85: 1-3
