Abu Dawud Book 2, Hadith Number 1317.
Chapter : The time when the prophet peacebeuponhim used to get up at night for prayer.
Narated By Anas : (Explaining the meaning) of the following Qur’anic verse: “They used to sleep but little of the night” (ii. 7): They (the people) used to pray between the sunset and the night prayers. The version of Yahya adds: The verse tatajafa junubhum also means so.