Moffatt(i)
16 Now the Promises were made to Abraham and to his offspring; it is not said, 'and to your offsprings' in the plural, but in the singular and to your offspring — which is Christ.
17 My point is this: the Law which arose four hundred and thirty years later does not repeal a will previously ratified by God, so as to cancel the Promise.
18 If the Inheritance is due to law, it ceases to be due to promise. Now it was by a promise that God bestowed it on Abraham.
19 Then what about the Law? Well, it was interpolated for the purpose of producing transgressions till such time as the Offspring arrived to whom the Promise was made; also, it was transmitted by means of angels through the agency of an intermediary