If they say, Come with us, let us lay wait for {k} blood, let us lurk privily for the innocent without cause:

(k) He speaks not only of the shedding of blood with hand, but of all crafty practises which tend to the detriment of our neighbour.

Jamieson-Fausset-Brown Bible Commentary

11-14. Murder and robbery are given as specific illustrations.

lay wait . lurk privily-express an effort and hope for successful concealment.

swallow . grave-utterly destroy the victim and traces of the crime (Nu 16:33; Ps 55:15). Abundant rewards of villainy are promised as the fruits of this easy and safe course.

Matthew Henry's Concise Commentary

1:10-19 Wicked people are zealous in seducing others into the paths of the destroyer: sinners love company in sin. But they have so much the more to answer for. How cautious young people should be! Consent thou not. Do not say as they say, nor do as they do, or would have thee to do; have no fellowship with them. Who could think that it should be a pleasure to one man to destroy another! See their idea of worldly wealth; but it is neither substance, nor precious. It is the ruinous mistake of thousands, that they overvalue the wealth of this world. Men promise themselves in vain that sin will turn to their advantage. The way of sin is down-hill; men cannot stop themselves. Would young people shun temporal and eternal ruin, let them refuse to take one step in these destructive paths. Men's greediness of gain hurries them upon practices which will not suffer them or others to live out half their days. What is a man profited, though he gain the world, if he lose his life? much less if he lose his soul?