"for they shall eat the fruit of their doings."
This is more of Isaiah letting everyone know that they will ultimately (and not so ultimately) get returned to you what you do. Isaiah 3:9-11 9 ¶ The shew of their countenance doth witness against them; and they declare their sin as Sodom , they hide it not. Woe unto their soul! for they have rewarded evil unto themselves. 10 Say ye to the righteous , that it shall be well with him: for they shall eat the fruit of their doings. 11 Woe unto the wicked ! it shall be ill with him: for the reward of his hands shall be given him. Sometimes, we concentrate on the bad side of our doings, but Isaiah is good to say that as we are righteous, we will have good things come to us. Rewards and justice are indeed two-edged!