سنن النسائي

It was narrated from Salim bin Abdullah that: Abdullah bin Umar came to Al-Hajjaj bin Yusuf on the day of Arafat when the sun has passed its zenith, and I was with him. He said: "We have to move on if you want to follow Sunnah." He said to him: "At this hours?" He said: Yes." Salim said: "I said to Al-Hajjaj: 'If you want to follow the Sunnah, then deliver a short Khutbah and hasten to pray.' Abdullah bin Umar said: 'He is telling the truth.'"