سنن أبي داود

Narrated Al-Harith ibn Amr as-Sahmi:

I came to the Messenger of Allah (ﷺ) when he was at Mina, or at Arafat. He was surrounded by the people. When the bedouins came and saw his face, they would say: This is a blessed face. He said: He (the Prophet) appointed Dhat Irq as the place of putting on ihram for the people of Iraq.