A good man leaveth an inheritance to his children's children: and the wealth of the sinner is laid up for the just.
A good (man) leaveth an inheritance to his children's children - i:e., presuming that the children and grand-children taught by the good man follow his steps.
And the wealth of the sinner is laid up for the just. This is one instance of the principle in Proverbs 13:21. The expression, "is laid up," implies that there are hidden ways whereby God sustains the godly, though they do not see it with their eyes nor can comprehend it with their mind (T. Cartwright).