Sayyidina Abdur Rahman ibn Yamur (RA) said that some people of Najd met Allahs Messenger(SAW) while he was at Arafat. They asked him (about Hajj), so he ordered an announcer to proclaim and he proclaimed that Hajj was (the standing) at Arafah. One who reaches Arafat before rise of dawn on the night of Muzdalifah has, indeed, performed Hajj. The days of Mina are three days, but Then whosoever hastens (his departure) after his stay of two days (at Mina) there is no sin on him and whosoever delays there is no sin on him. (2 203) Muhammad said that Yahya added, The Prophet (SAW) took a co-rider and got him to proclaim.
[Ahmed18976, Abu Dawud 1949, Nisai 3016, Ibn e Majah 3015]