Musar zu Mischlej 11:13

And there is another sin which is called tale-bearing. Now, who is a tale bearer? One who loads himself with stories about others and goes from one to another and says, "Thus did so and so say," and "Thus and thus did I hear about that one." Even though what he tells is true, this kind of thing destroys the world. And we have been warned about this, as it is written, "Thou shall not go up and down as a tale-bearer among thy people" (Lev. 19:16). And what is tale-bearing? One who reveals to another things that were said about him in secret, and we have learned (Sanh. 31a): "Whence do we know that when a judge comes out he must not say, 'I was for acquittal, while my colleagues were for condemnation; but what could I do, seeing that they were in the majority?' " Scripture states, "Thou shall not go up and down as a tale-bearer among thy people" (Lev. 19:16), and further, "He that goeth about as a tale-bearer revealeth secrets" (Prov. 11:13).