Reference: Safahaat Mushriqah min Hayaat al-Imaam Muhammed ibn Saalih al-‘Uthaymeen – Page 73
Muhammad ibn ‘Abdil-Jawwaad as-Saawee narrates:
Once the Shaykh was invited by one of the charity organisations in Jeddah, and the meeting prolonged into the night, close to one o’clock in the morning; and it was not the habit of the Shaykh to remain awake like this. It was noticeable that he was overcome with exhaustion and tiredness and it was evident he needed sleep, so we returned to the house where the Shaykh was staying, and we entered and fell asleep right away.
In the middle of the night, at about 3:30, after we had been sleeping for about only two hours – since we fell asleep at about 1:30 – I noticed the sound of the Shaykh reciting in prayer; and this at a time when he was desperately in need of sleep and rest, [yet] he was standing before his Lord praying.