Paul's Bodily Illness
Could this be what Paul describes as his thorn in the flesh? (2 Corinthians 12:7).
Regarding this section, Wiersbe writes: Paul was a wonderful spiritual father; he knew just how to balance rebuke with love. Now he turns from “spanking” to “embracing” as he reminds the believers of their love for him and his love for them.
At one point they were willing to sacrifice anything for Paul, so great was their love; but now he had become their enemy. The Judaizers had come in and stolen their affection.
Bible students wish Paul had been more explicit here, because we are not sure just what events he is talking about. When Paul had originally visited them, he was suffering from some physical affliction.
If Paul wrote this letter to the churches of South Galatia, then he is referring to his first missionary journey, recorded in Acts 13–14. Apparently Paul had not intended to visit these cities, but was forced to do so because of some bodily infirmity. We can only speculate as to what this was. Some have suggested malaria; others, an affliction of the eyes (see Galatians 4:15, 6:11). Whatever it was, it must have made Paul somewhat repulsive in appearance, because he commends the Galatians for the way they received him in spite of the way he looked. To them, he was an angel of God. It is a wonderful thing when people accept God’s servants, not because of their outward appearance, but because they represent the Lord and bring his message.
Galatians 4:13–15New American Standard Bible: 1995 Update
but you know that it was because of a bodily illness that I preached the gospel to you the first time;
and that which was a trial to you in my bodily condition you did not despise or loathe, but you received me as an angel of God, as Christ Jesus Himself.
Where then is that sense of blessing you had? For I bear you witness that, if possible, you would have plucked out your eyes and given them to me.