Expositor's Bible Commentary Commentary Mark 9:42

"And whosoever shall cause one of these little ones that believe on me to stumble, it were better for him if a great millstone were hanged about his neck, and he were cast into the sea." — Mark 9:42 (ASV)

This verse is probably better taken with what precedes it than with what follows. The warning points back to the disciples’ attempt to prevent the unknown exorcist from doing his work in Jesus’ name (v.38) or to prevent anyone from giving a cup of water in his name. “Little ones” refers to followers of Jesus, and “to sin” means to prevent them from acting in Jesus’ name. The offense is so serious that it would have been better for one to be drowned than to commit it.