Make thee sharp knives - Render rather as marg., and compare marginal reference and note. Knives of flint or stone were in fact used for circumcision, and retained for that and other sacred purposes, even after iron had become in common use. The rendering of the margin is adopted by almost all ancient versions, by most commentators, and by the fathers generally, who naturally regarded circumcision performed by Joshua and by means of knives of stone or rock, as symbolic of the true circumcision performed by Christ, who is more than once spoken of as the Rock (compare 1 Corinthians 10:4; Romans 2:29; Colossians 2:11). See Joshua 21:42.
Circumcise again ... - i. e. make that which once was a circumcised people but is not so now, once more a circumcised people. (See Joshua 4:4-7.)