Hebrews 7:18-21

For there is a disannulling of a foregoing commandment because of its weakness and unprofitableness (for the law made nothing perfect), and a bringing in thereupon of a better hope, through which we draw nigh unto God. And inasmuch as it is not without the taking of an oath (for they indeed have been made priests without an oath; but he with an oath by him that saith of him, The Lord sware and will not repent himself, Thou art a priest for ever)