Sunan Abi Dawud 419
سنن أبي داود#419SahihNarrated An-Nu'man ibn Bashir: I am the one who is best informed of the time of this prayer, i.e. the night prayer. The Messenger of Allah (ﷺ) used to offer it at the hour when the moon went down on its third night
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Al-AlbaniSahih
Muhammad Muhyi Al-Din Abdul HamidSahih
Shuaib Al ArnautSahih
Zubair Ali ZaiIsnaad Sahih
In-book reference: 2:29