Musnad Ahmad 26:99

Yahya ibn Sa'id narrated to us, from Sufyan, Sulayman narrated to me, from Abu Wa'il, from Abdullah, who said: "I prayed with the Prophet, peace and blessings of Allah be upon him, one night, and he kept standing until I intended to do a bad thing." We said: "And what did you intend to do?" He said: "I intended to sit down and leave him."