Ben Sira 12:11

11 Watch out, and be on guard against him, even if he acts ever so humble. He is like a metal mirror that rusts away if you don't keep it polished.

Ben Sira 12:11 In-Context

9 even your friends will leave you then. But when you are successful, your enemies will act like friends.

10 Never trust an enemy; his wickedness is as destructive as rust.

11 Watch out, and be on guard against him, even if he acts ever so humble. He is like a metal mirror that rusts away if you don't keep it polished.

12 Seat an enemy at your right hand, and the next thing you know he'll be trying to get your own place of honor. Put him next to you, and he will overthrow you. Then you will realize the truth of my words, and be stung with regret when you remember them.

13 Nobody feels sorry for snake charmers or wild animal tamers who get bitten,