'Rigour' in the Bible

Thou shalt not rule over him with rigour; but shalt fear thy God.

And ye shall take them as an inheritance for your children after you, to inherit them for a possession; they shall be your bondmen for ever: but over your brethren the children of Israel, ye shall not rule one over another with rigour.

And as a yearly hired servant shall he be with him: and the other shall not rule with rigour over him in thy sight.