Bedikat HaSakin (“Checking of the Knife”) is a 13th-century treatise on the process of checking the knife used for ritual slaughter and checking an animal for defects or injuries that would render it a terefah (an animal disqualified from being kosher because of defects or injuries), by Rabbeinu Yonah Gerondi. It was first printed in the 19th century in the back of Teshuvot HaGeonim.