John Gill's Bible Commentary Ver. 1. Now these [are] the nations which the Lord left to prove Israel by them , etc.] Which are later mentioned, ( Judges 3:3,5); [even] as many [of Israel] as had not known all the wars of Canaan ; those that Joshua, and the people of Israel under him, had with the Canaanites, when they first entered the land and subdued it; being then not born, or so young as not to have knowledge of them, at least not able to bear arms at that time.
Matthew Henry Commentary
Verses 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 remain 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 forbidde to conform to it. This marks the difference between the followers of Christ and mere professors. The friendship of the world is more fata than its enmity; the latter can only kill the body, but the forme murders many precious souls.
Original Hebrew ואלה428 הגוים1471 אשׁר834 הניח3240 יהוה3068 לנסות5254 בם את853 ישׂראל3478 את853 כל3605 אשׁר834 לא3808 ידעו3045 את853 כל3605 מלחמות4421 כנען׃3667