Matthew Henry's Concise Commentary

3:1-7 As the Israelites were a type of the church on earth, they were not to be idle and slothful. The Lord was pleased to try them by the remains of the devoted nations they spared. Temptations and trials detect the wickedness of the hearts of sinners; and strengthen he graces of believers in their daily conflict with Satan, sin, and this evil world. They must live in this world, but they are not of it, and are forbidden to conform to it. This marks the difference between the followers of Christ and mere professors. The friendship of the world is more fatal than its enmity; the latter can only kill the body, but the former murders many precious souls.