What does Paul mean when he says that the law does not annul the covenant previously ratified by God?
Paul refers to the Mosaic law.1 It is likely that some of the Judaizers were claiming that Mosaic law supplemented and defined the Abrahamic covenant.2 Paul makes it clear that this is not the case. The covenant with Abraham takes precedence over the covenant made through Moses since it came first.3 The agreement with Abraham is not annulled or changed by the agreement made through Moses.4
17 Voici ce que je veux dire: un testament, que Dieu a confirmé antérieurement, ne peut pas être annulé, et ainsi la promesse rendue sans effet, par la loi survenue quatre cent trente ans plus tard.