Legal documents are signed and dated. Dates establish the precedence of one document over another. In the case of a will, a subsequent codicil or new will can annul or change the terms of the previous document. So lawyers search to make sure they have the document with the latest date which overrides all previous documents.

In the case of an irrevocable trust agreement, however, subsequent documents cannot overturn the terms of the original document. Paul has this type of document in mind. He carefully notes that the date on the irrevocable trust agreement made with Abraham places that covenant 430 years before the Mosaic law. If the Mosaic law and the Abrahamic covenant had the same date, then one might suppose that the Mosaic law should be included in the understanding of the terms of the Abrahamic covenant. But the fact that the Mosaic law came 430 years after the Abrahamic covenant indicates that the two should be clearly distinguished from each other and that the terms of the Abrahamic covenant should not be confused with or changed by the terms of the Mosaic covenant.

This distinction between the time of the confirmation of the promise to Abraham and that of the giving of the law stands in stark contrast to the rabbinic claim that Abraham knew and kept even the minutest details of the Mosaic law. In Jewish tradition the Mosaic law had been inseparably linked with the Abrahamic covenant. Influenced by this perspective, the Galatian believers had come to think that it was necessary to keep the Mosaic law to inherit the blessings promised to Abraham. In Paul's view, those who seek the inheritance through the law have failed to recognize the precedence of the promise in salvation history. They have failed to realize that because the law came 430 years after the promise it could not annul or be attached to the promise as a condition of inheriting the promised blessings.

Since Paul equates the promise and the gospel, the distinction he sees between promise and law is also a distinction between gospel and law. Those who minimize or deny this contrast between gospel and law need to consider the radical nature of Paul's distinction.