I saw Bilal bringing a short spear (or stick) and fixing it in the ground, and then he proclaimed the
Iqama of the prayer, and I saw Allah's Messenger (ﷺ) coming out, wearing a cloak with its sleeves rolled up.
He then offered a two-rak`at prayer while facing the stick, and I saw the people and animals passing in
front of him beyond the stick.
Sahih al-Bukhari Book 77, Hadith 4