Musannaf Ibn Abi Shayba 35:7

Hushaym narrated to us, from Yunus, from al-Hasan, from Abdullah ibn Mughaffal, who said: The Messenger of Allah (may Allah bless him and grant him peace) said: "Pray in the resting places of sheep, and do not pray in the resting places of camels, for they were created from the devil."