Musnad Abu Ya'la al-Mawsili 42:31

Al-Hasan ibn 'Arafah narrated to us, Hushaym narrated to us, from Mujalid, from Abu al-Wadak, from Abu Sa'id, from the Prophet (peace be upon him), who said: "There are three whom Allah laughs at on the Day of Resurrection: a man when he stands at night to pray, a group when they stand in rows for prayer, and a group when they stand in rows to fight the enemy."