And James the son of Zebedee, and John the brother of James; and he surnamed them Boanerges, which is, The sons of thunder:
All Commentaries on Mark 3:17 Go To Mark 3
Eusebius of Caesarea
AD 339
Thunder here refers to the preaching of the gospel. For as a heavenly shout occurs like a voice of thunder, surpassing all human power, in the same way also the preaching of the gospel, which is a heavenly happening, does not consist of human strength. The gospel did not fill the world by human planning, but by divine power.