Musnad Ahmad 30:3767

He said: "If people knew what there is in the call (Adhan) and the first row, and then they could not find a way except to draw lots for them, they would draw lots for them. And if they knew what there is in arriving early (to the prayer), they would race toward it. And if they knew what there is in the night prayer (Isha) and the dawn prayer (Fajr), they would come to them even if they had to crawl."