'This Will Be the Sign' in the Bible

" 'This will be the sign for you: Eat the volunteer plants for the year, and in the second year, the volunteer plants that spring up from that. But [in] the third year, sow and reap, plant vineyards and eat their fruit.

And Isaiah said, This will be the sign from Jehovah, that Jehovah will do the thing which He has spoken. Shall the shadow go forward ten steps, or go back ten steps?