Expositor's Bible Commentary Commentary Mark 1:19

"And going on a little further, he saw James the [son] of Zebedee, and John his brother, who also were in the boat mending the nets." — Mark 1:19 (ASV)

The same call that was extended to Peter and Andrew was now extended to James and John, sons of Zebedee, and they too responded without any hesitation. In their case something of the price of discipleship is indicated by the breaking of family ties—the leaving of their father’s business.