The mountains shall bring peace to the people - The idea in this verse is that the land would be full of peace and the fruits of peace. All parts of it would be covered with the evidences that it was a land of quietness and security, where people could pursue their callings in safety, and enjoy the fruit of their labors. On the mountains and on all the little hills in the land there would be abundant harvests, the result of peace (so strongly in contrast with the desolations of war) - all showing the advantages of a peaceful reign. It is to be remembered that Judea is a country abounding in hills and mountains, and that a great part of its former fertility resulted from terracing the hills, and cultivating them as far as possible toward the summit. The idea here is, that one who should look upon the land - who could take in at a glance the whole country - would see those mountains and hills cultivated in the most careful manner, and everywhere bringing forth the productions of peace. Compare Psalms 65:11-13. See also the notes at Psalms 85:11-12.
And the little hills, by righteousness - That is, By the prevalence of righteousness, or under a reign of righteousness, the little hills would furnish illustrations of the influence of a reign of peace. Everywhere there would be the effects of a reign of peace. The whole land would be cultivated, and there would be abundance. Peace always produces these blessings; war always spreads desolation.