Sahih Muslim
The Book of Drinks (Kitab Al-Ashriba)
Book Number: 023 / Hadith Number: 4998
Jabir reported Allah's Messenger (may peace be upon him) as saying: Do not let your animals and children go out when the sun sets until the first and the darkest part of the night is over, for the Satan is let loose with the sinking of the sun until the darkest part of the night is over.