Contrast of Paul's own boasting and its ground with those of the false apostles.
By whom (δι' οὗ)
The relative may refer either to the cross, by which, or to Christ, by whom. The cross was a stumbling-block to the Jews (Gal 3:13), and it is the crucified Christ that Paul is emphasizing. Comp. Gal 2:20; Gal 5:24.