Musnad Ahmad 30:903

I read to Abd al-Rahman: Malik, from Sumayy, the freed slave of Abu Bakr ibn Abd al-Rahman, from Abu Salih al-Samman, from Abu Hurayrah, that the Messenger of Allah (peace and blessings of Allah be upon him) said: "If the people knew what is in the call (to prayer) and the first row, and then they could not find [a way to attain it] except by drawing lots for it, they would draw lots for it. And if they knew what is in arriving early (to the prayer), they would race toward it. And if they knew what is in the night prayer (Isha) and the dawn prayer (Fajr), they would come to them even if they had to crawl."