A dramatic shift in the agricultural landscape brings about a surprising new reality, where difficult, mountainous terrain becomes a center of blessing, security, and abundance. The focus turns to rugged mountains that are manually dug and cultivated with hand hoes rather than standard plows [רד״ק, מצודת ציון, ביאור שטיינזלץ], or areas where harmful weeds and roots are carefully uprooted by hand [שד״ל]. In these specific locations, there will be no fear of thorns and wild brush taking over the soil.
From a practical and topographical standpoint, high, rocky mountains cannot be plowed normally and must be worked manually. Because of this targeted effort, the wild thorns that are expected to overrun the valleys and the rest of the land will fail to conquer the mountain peaks [מלבי״ם, ביאור שטיינזלץ]. Furthermore, these rugged highlands, which once served as dangerous hideouts for robbers, will be transformed into safe, cultivated zones [אברבנאל].
A historical and spiritual perspective links this transformation to the reign of King Hezekiah. The mountains represent fields dedicated to growing essential grain. During that era, the people repented and completely changed their daily habits. They abandoned the pursuit of luxuries, such as drinking wine, and instead devoted their time to studying Torah. As a result, the vineyards were neglected and overgrown with thorns, while the grain fields were meticulously tended with hoes, simply because survival requires bread [רש״י, מצודת דוד, אברבנאל]. Another view suggests that these mountains were actually former vineyards destined for rehabilitation. God will bestow such an enormous blessing upon them that they will become entirely clear of any thorns [אבן עזרא].
Thanks to this careful cultivation and divine blessing, these areas will become fertile, rich pastures where oxen and sheep are sent to roam freely, stepping and treading openly across the earth [מצודת ציון]. There will be such profound peace and an overwhelming abundance of crops that the landowners will not even worry about the animals eating or trampling the fields [רש״י, רד״ק, מצודת דוד, אברבנאל]. Ultimately, this creates a striking reversal: the rugged, less valued places that are hardest to work become settled and full of life, while the once-prized regions of the past are left in desolation [מלבי״ם].