Wiktionary
live off the land
vb. to sustain a living by eating produce that one harvests or hunts from the countryside.
Usage examples of "live off the land".
We are honest soldiers, all of us, forced to live off the land when our officer deserted us.
One thing Larssen had proved, traveling cross-country from White Sulphur Springs to Chicago and then from Denver to Hanford and back again: he knew how to live off the land.
Even the Hyead couldn't live off the land here, between the mountains and the sea.
Grampa claims that if Muley can stay behind and live off the land, so can he.