Musnad Ahmad 789:42

Hassan ibn Musa narrated to us, Sakeen ibn Abd al-Aziz narrated to us, from Sayyar ibn Salamah, Abu al-Minhal al-Riyahi, who said: I entered with my father upon Abu Barzah al-Aslami, and I had two earrings in my ears that day, and I was a young boy. He said: Abu Barzah said: "I praise Allah that I have reached this morning blaming this tribe of Quraysh. So-and-so is here fighting for the world, and so-and-so is here fighting for the world"—meaning Abd al-Malik ibn Marwan. He said: Until he mentioned Ibn al-Azraq. He said: Then he said: "The most beloved of people to me are this group whose bellies are empty of the wealth of the Muslims, and whose backs are light from their blood." He said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "The leaders are from Quraysh. The leaders are from Quraysh. The leaders are from Quraysh. They have a right over me, and you have a right over them, as long as they do three things: as long as they judge and are just, and are asked for mercy and show mercy, and make a covenant and fulfill it. Whoever among them does not do that, then upon him is the curse of Allah, the angels, and all of mankind."