Musnad Ahmad 955:2

Waki’ narrated to us, Al-Aswad ibn Shayban narrated to me, from Khalid ibn Samir, from Bashir ibn Nahik, from Bashir ibn al-Khasasiyyah—the one who gave the glad tidings to the Messenger of Allah (peace be upon him): That the Prophet (peace be upon him) saw a man walking among the graves wearing two sandals. He said: "O owner of the two Sabtiyyah sandals, cast them off."