By thy sword shalt thou live; by violence and rapine, in an unquiet and military posture, troubling others, and forced to defend thyself. But this, as also the following clause, though spoken to Esau, was not fulfilled in him, but in his posterity the Edomites, whose history makes good this prophecy. Thus things spoken and promised to Abraham were fulfilled in his posterity, as Gen_12:3 22:18.
When thou shalt have the dominion; when thou shalt grow potent. Some render the words thus, When thou shalt have mourned or groaned, as the same word is used Psa_55:2; when thou hast oppressed as long as I think fit.