Musannaf Ibn Abi Shaybah 3390 — Staying away from Isha and Fajr

Ibn Abi Amrah al-Ansari said: I came to the mosque, and Sayyiduna Uthman (may Allah be pleased with him) was sitting in the mosque at the time of the Isha prayer, so I sat with him. Sayyiduna Uthman said: Attending the Fajr prayer is like worshipping the whole night, and attending the Isha prayer is like worshipping half the night.