'Fro' in the Bible

But the olive-tree said unto them, Should I leave my fatness, wherewith by me they honor God and man, and go to wave to and fro over the trees?

But the fig-tree said unto them, Should I leave my sweetness, and my good fruit, and go to wave to and fro over the trees?

And the vine said unto them, Should I leave my new wine, which cheereth God and man, and go to wave to and fro over the trees?