This year … the second year … the third year: Due to the Assyrian siege and its impact on farming, the people of Judah could not plant and harvest as usual. The promise that life would return to normal after the siege reassured them that God was with them and would provide for their daily needs. They needed to build their trust in God over three years, believing that God's word would come true (see Isaiah 30:15, 18).
The idea was that after escaping the Assyrians, it would be too late to plant in the current year. They would have to wait until the fall of the second year to plant again and would harvest their first crop in the spring and summer of the third year.