Galatians 3:15-16

Brethren, I speak after the manner of men; Though {it be} but a man's covenant, yet {if it be} confirmed, no man disannulleth, or addeth thereto. {covenant: or, testament} Now to Abraham and his seed were the promises made. He saith not, And to seeds, as of many; but as of one, And to thy seed, which is Christ.