As the days of a tree are the days of my people. Trees endure for many hundreds, perhaps for thousands of years. The cedars of Lebanon, the oaks of Bashan, were known to have an antiquity of centuries.
Isaiah may have had a knowledge of other trees to which attached the tradition of a yet longer existence. In our own day Brazil and California have furnished proofs of vegetable growths exceeding a millennium.
Mine elect shall long enjoy; literally, shall wear out; i.e. have the full use and enjoyment of the work of their hands.