The people living in the mountains and land of Israel permanently is spoke of as if the people would inherit them. Alternate translation: "They will possess you permanently" (See: [[rc://en/ta/man/translate/figs-metaphor]])
It is implied that in the past children died because there was not enough food in the land. Now the land would produce enough food. (See: [[rc://en/ta/man/translate/figs-explicit]])