* sharp knives.  or, knives of flints.
   Before the use of iron was common, all the nations of the
   earth had their edge tools made of stones, flints, etc.  Our
   ancestors had their arrows and spearheads made of flint; which
   are frequently turned up by the plough.  And even when iron
   became more common, stone knives seem to have been preferred
   for making incisions in the human body.  The Egyptians used
   such to open the bodies for embalming; and the tribe of
   Alnajab in Ethiopia, who follow the Mosaic institution,
   perform the rite of circumcision, according to Ludolf,
   {cultris lapidibus,} with knives made of stone.

 * circumcise.
  Ge 17:10-14  De 10:16  30:6  Ro 2:29  4:11  Col 2:11