Biblion Bible Commentary
Read the introduction to Galatians · About this commentary
And to Your Offspring
Galatians 3:15-18
15 Brothers, speaking of human terms, though it is only a man’s covenant, yet when it has been confirmed, no one makes it void or adds to it. · WEB
A point of ordinary contract law is applied to the covenant, and the interval between promise and Sinai is given in years.
Paul argues from common practice first: though it is only a man's covenant, once ratified no one voids it or adds to it. Even in human dealings a settled agreement is not amended by a later party.
Then verse 16, and the argument rests on a grammatical observation: the promise was spoken to Abraham and to his offspring, and the noun is singular. He does not say, to descendants, as of many, but as of one. The Hebrew word is a collective — it can cover a whole line, as English offspring does — and Paul presses the singular form to identify the recipient as Christ.
The move needs stating carefully rather than dismissed or overclaimed. Paul is not denying the word can be collective; the same chapter ends by calling believers Abraham's offspring, singular, of a plural body Galatians 3:29. What he draws from it is that the promise always terminated on one, and the many are included by belonging to that one.
Verse 17 supplies the interval: the law came four hundred thirty years after the covenant was confirmed. A codicil written four centuries later cannot annul the original grant, and Paul's word for the effect is that it cannot make the promise of no effect.
Verse 18 states the alternative as an exclusive choice. If the inheritance comes by law, it no longer comes by promise — and the record is that God granted it to Abraham by promise. The verb is a gift word, from the same root as grace.
settled What this mark means