'Added' in the Bible

But of these who seemed to be somewhat, (whatsoever they were, it maketh no matter to me: God accepteth no man's person:) for they who seemed to be somewhat in conference added nothing to me:

Brethren, even a covenant made by a man--to borrow an illustration from daily life--when once formally sanctioned is not liable to be set aside or added to.

Wherefore then serveth the law? It was added because of transgressions, till the seed should come to whom the promise was made; and it was ordained by angels in the hand of a mediator.