And all the men of his house
 All the males, whether children or adult: 
 born in the house, or bought with money of the stranger, were
 circumcised with him;
 by their will, and with their consent; not forced to it, as Aben Ezra rightly observes; and these being before trained up by him in religious exercises, were more easily prevailed upon by him to follow his example; this also is repeated, that it might be served, and be an example to follow in after generations.