Wisdom of Ben Sira 12:9-11

New Catholic Bible

⁹ When you prosper even your enemies are grieved,^[a]
    but in adversity even your friends will shun you.
¹⁰ Never trust your enemy;
    just as bronze tarnishes, so does his wickedness.
¹¹ Even if he acts humbly and in a subservient manner,
    take care to be on your guard against him.
Behave toward him as if you were polishing a mirror,
    and you will see that his tarnish does not last.