Charles Spurgeon Commentary Galatians 4:13-14

"but ye know that because of an infirmity of the flesh I preached the gospel unto you the first time: and that which was a temptation to you in my flesh ye despised not, nor rejected; but ye received me as an angel of God, [even] as Christ Jesus." — Galatians 4:13-14 (ASV)

Ye know how through infirmity of the flesh I preached the gospel unto you at the first. And my temptation which was in my flesh ye despised not, nor rejected; but received me as an angel of God, even as Christ Jesus.

He dwells on that. They had been so enthusiastic about his teaching when he first taught them, that he feels grieved that now they have turned to other teaching – not because it injured him, but because it injured them.