Sunan At-Tirmidhi

Fadalah bin 'Ubaid narrated that when the Messenger of Allah (s.a.w) would lead the people in Salat some men would collapse among them during the Salat due to hunger – they were among them Ashab As-suffah – such that a Bedouin would say :'These people are mad' or ""possessed."" So when the Messenger of Allah (s.a.w) finished the Salah, he turned to them and said: 'If you knew what was in store for you with Allah then you would love to be increased in poverty and need.'” Fadalah said: “And on that day, I was with the Messenger of Allah(s.a.w).” (Hasan)