Musnad Ahmad 26:868

Muhammad ibn Ja‘far narrated to us, Shu‘bah narrated to us, he said: I heard Mansur narrating from Khaythamah ibn ‘Abd al-Rahman, from ‘Abdullah, from the Prophet, peace and blessings of Allah be upon him, that he said: "There is no late-night conversation except for two men, or for one of two men: for one who is praying, or for a traveler."