NET
19 Why then was the law given? It was added because of transgressions, until the arrival of the descendant to whom the promise had been made. It was administered through angels by an intermediary.
Darby
19 Why then the law? It was added for the sake of transgressions, until the seed came to whom the promise was made, ordained through angels in [the] hand of a mediator.
KJV
19 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.