Sayyiduna Aws bin Hudhayfah (may Allah be pleased with him) said: We came to the Messenger of Allah (peace and blessings be upon him), and the Messenger of Allah (peace and blessings be upon him) would come to us every night and talk with us. One night he (peace and blessings be upon him) was late, so we said: What happened to you? He (peace and blessings be upon him) said: "A portion of the Qur'an remained due upon me, and I wished not to go out without completing it."
Hadith Referenceالمعجم الكبير للطبراني / باب الألف / 596