Targum zu Dewarim 14:22

Be mindful to tythe your fruitage of whatsoever cometh forth, and which you gather in from the field year by year; not giving the fruit of one year for the fruit of another.

My people of the house of Israel, tything you shall tythe all the produce of your seed, of that which you sow upon the face of the field and gather in the produce of each year. Israel, My people, it is not lawful for you to tythe and eat the fruit of one year along with the fruit of (another) year.