Paul now gives a further reason why a man should not submit to circumcision. In verse 2 he has stated what would be lost: they would lose Christ. Here he states what would be gained: they would gain the whole Law; but this would be at the price of loss of freedom.

Once more (literally “again”) can be interpreted to refer either to an earlier statement of Paul (perhaps made on the occasion referred to in 4.16 and 1.9) or to the verse immediately preceding. The close relation between the two verses tends to give more weight to the latter of these (Phillips “I will say it again”).

I warn is literally “I testify.” The verb can be used to mean “to declare” or “to protest,” but here it has the primary meaning of “to warn” (Jerusalem Bible “I repeat my warning”; Knox compare New English Bible “you can take it from me”). After a verb such as warn, it may be necessary in a number of languages to use direct discourse, for example, “Once more I warn any man who lets others circumcise him, You must now obey the whole Law,” or “… every regulation in the Law.”

As in verse 2 Paul is addressing someone who has apparently not yet been circumcised but is about to submit to that rite. Paul’s warning is clear: anyone who receives circumcision is obliged to obey the whole Law. Paul has already discussed certain aspects of this problem in relation to Christ (see the comments on 3.7-14, especially verse 10). Circumcision is only one part of the Law, but to accept it is to obligate oneself to obey everything in the Law. As in several other contexts, the reference to Law may need to be translated as “the laws given by means of Moses.” However, the Law here may possibly be understood as referring to the whole body of laws found in the Old Testament, together, perhaps, with other laws that developed out of the Old Testament tradition. In that case the whole Law may be translated as “every one of the regulations of the laws,” or “every one of the specific laws.”

Quoted with permission from Arichea, Daniel C. and Nida, Eugene A. A Handbook on Paul’s Letter to the Galatians. (UBS Handbook Series). New York: UBS, 1976. For this and other handbooks for translators see here .