The Source of Contention

.... Paul had entered Achaia on a self-sufficient basis, and the men of that region never saw anything else from him (1 Corinthians 9:14,15). So this criticism must have come from an outside source. Rumors of the dispute in Amphipolis had caught up to him at last. To establish that this argument came from Amphipolis, rather than a Jewish source, let’s revisit the background and consider the terms of Paul’s response:

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.... Paul’s arguments with the Jews of Macedonia were recounted in detail, yet no issues over offerings were mentioned. Indeed, the Jewish leaders themselves received offerings, so they could not have criticized him without implicating themselves. This made a Jewish source for the criticism  unlikely.

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.... In fact, in a strange twist of fate, the Jews of Thessalonica had probably become a staunch barrier to help shield him from that criticism, and had probably kept it at bay for a long time. When it came to their city they would have defended the right to receive offerings, but would also have to admit that Paul, himself, had not used this right. This would make them more sensitive to the criticism than he was. So their only recourse would have been to play it down.

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.... The underlying nature of this criticism suggests a Gentile mind; and for the same reason, Paul began his defense with analogies and only used Scriptures to support the analogies. This indicates that his critics would have considered that justification to be self-serving. In other words his critics were Gentiles, who were strangers from the covenants of God.

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.... The case for the lost ministry of Amphipolis may be read between the lines in the nature of the arguments that followed Paul. The intensity and effect of those charges may be measured through the sincerity and urgency of his defense, and the frequent repetition of that defense in the Scriptures he provided over the years.