Musannaf Ibn Abi Shayba 3:1435

Husayn ibn Ali narrated to us, from Za'idah, from Abd al-Aziz ibn Rufay', from Amir ibn Mas'ud al-Qurashi, who said: The Messenger of Allah (may Allah bless him and grant him peace) said: "If the people knew what is in the first row, they would not have lined up in it except by drawing lots."