'Rigour' in the Bible

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

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

As a hired servant shall he be with him year by year; his master shall not rule with rigour over him before thine eyes.