Sirach 19:13-15

New Revised Standard Version Catholic Edition

¹³ Question a friend; perhaps he did not do it;
    or if he did, so that he may not do it again.
¹⁴ Question a neighbor; perhaps he did not say it;
    or if he said it, so that he may not repeat it.
¹⁵ Question a friend, for often it is slander;
    so do not believe everything you hear.