Musnad Ahmad 33:1020

Hassan narrated to us, Zuhair narrated to us, from Abu al-Zubayr, from Jabir, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "Do not let your livestock and your children out when the sun sets until the darkness of the night (fahmat al-isha) passes, for the devils spread out when the sun sets until the darkness of the night passes."