17. As one piece of iron sharpens another, so friends keep each other sharp.
18. People who take care of fig trees are allowed to eat the fruit. In the same way, people who take care of their masters will be rewarded.
19. Just as you can see your own face reflected in water, so your heart reflects the kind of person you are.
20. Just as the place of death and destruction is never full, people always want more and more.
21. People use fire to purify gold and silver. In the same way, you are tested by the praise people give you.