Sahih Bukhari Volume 4, Book 54, Hadith Number 523.

Narated By Jabir bin Abdullah : Allah’s Apostle said, “When night falls (or it is evening), keep your children close to you for the devils spread out at that time. But when an hour of the night elapses, you can let them free. Close the doors and mention the Name of Allah, for Satan does not open a closed door.”