Sirach 6:9

9 And there is a friend, who being turned to enmity, and strife will discover thy reproach.

Sirach 6:9 In-Context

7 If thou wouldest get a friend, prove him first and be not hasty to credit him.
8 For some man is a friend for his own occasion, and will not abide in the day of thy trouble.
9 And there is a friend, who being turned to enmity, and strife will discover thy reproach.
10 Again, some friend is a companion at the table, and will not continue in the day of thy affliction.
11 But in thy prosperity he will be as thyself, and will be bold over thy servants.

The Brenton translation of the Septuagint is in the public domain.