Sirach 6:7

7 If thou wouldest get a friend, prove him first and be not hasty to credit him.

Sirach 6:7 In-Context

5 Sweet language will multiply friends: and a fairspeaking tongue will increase kind greetings.
6 Be in peace with many: nevertheless have but one counsellor of a thousand.
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.

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