It is possible that we have said it before could refer to the statement in verse 8 (New American Bible “I repeat what I have just said”). Most translators and commentators, however, understand this statement to refer to a previous occasion in the past, when Paul was with the Galatians, in contrast with the present when he is not personally with them but is communicating with them by letter. This previous occasion is probably the initial visit of Paul to Galatia. If one takes the position that Paul is writing to congregations in the Roman province of Galatia, then perhaps a more or less accurate record of this visit can be found in Acts 13.13–14.26. In a number of languages, however, one cannot be ambiguous in the use of the adverb before. One must either choose the immediate reference to what is said in verse 8 or to what was said on a prior occasion. If one chooses the latter, it may be necessary to indicate something of the time lapse of the verb in question. Here, depending on one’s understanding of the date for the writing of the letter to the Galatians, one must choose between “several months before” or “a few years before.”
The we, as in verse 8, may be understood as referring to Paul himself (New English Bible, New American Bible, Jerusalem Bible, Phillips, Moffatt). An alternative is to understand we as referring not only to Paul but to his missionary companions when he visited the Galatians. This is apparently what Good News Translation prefers, and therefore it preserves the plural form in translation. In languages which would not employ the so-called “editorial we,” it may be better to employ the first person singular “I,” particularly if one understands that by we Paul is referring to himself alone.
The Greek word for if in the phrase if anyone indicates that Paul is no longer dealing with a supposition or a hypothetical situation (as in verse 8) but with the actual situation of the Galatian churches, and so it may be translated “whoever” or “anyone who.” Anyone is general, but the reference is, of course, to the some people of verse 7.
The one you accepted is literally “that which you received.” The word “received” contains the element of appropriating something for oneself. The good news had not merely been preached to the Galatians; they had not merely “heard” it (Jerusalem Bible, Phillips), but they had received it and made it their own. The Greek verb used in this context was a technical one in Judaism for “receiving a tradition.”
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 .