The Day of Arafat is the most blessed day of the year. It is the day in which Allah (swt) boasts to the angels about His servants gathered together. All of them covered in dust and dirt but calling on Allah and asking for His mercy.
The core of Hajj is contained in the actions on Arafat. On this day Allah (swt) draws near to the earth and asks “What are my servants asking for so that I may grant it to them?