Bashr bin al-Sari al-Afwah بشر بن السري أبو عمرو الأفوه · The Book on Salat (Prayer)

Allah's Messenger said: "Whoever attends Isha (prayer) in congregation, then he has (the reward as if he had) stood half of the night. And whoever prays Isha and Fajr in congregation, then he has (the reward as if he had) spend the entire night standing (in prayer)."