'Olive tree' in the Bible

And, if some of the branches were broken off, and you, being a wild olive, were grafted in among them, and became a joint-partaker of the root and of the fatness of the Olive tree;

For, if you were cut out of that which is by nature a wild olive tree, and were grafted, contrary to nature, into a good olive tree; how much more shall these, the natural branches, be grafted into their own olive tree?