Isaiah 37:30

And this [shall be] a (y) sign to thee, Ye shall eat

[this] year such as groweth of itself; and the (z) second year that which springeth of the same: and in the third year sow ye, and reap, and plant vineyards, and eat the fruit of them.

(y) God gives signs after two sorts: some go before the thing as the signs that Moses worked in Egypt, which were for the confirmation of their faith, and some go after the thing, as the sacrifice, which they were commanded to make three days after their departure: and these latter are to keep the blessings of God in our remembrance, of which sort this here is.

(z) He promises that for two years the ground would feed them of itself.