Musnad Ahmad 1092:4

Isma'il narrated to us, 'Uthman al-Batti informed us, from 'Abd al-Hamid ibn Salamah, from his father, that the Messenger of Allah (peace and blessings of Allah be upon him) forbade the pecking of the crow, the spreading of the beast, and that a man should designate a specific place for himself in the prayer just as a camel designates its place.