The book of King Solomon’s wisdom reveals that the sign for transgression is a body illness. A sign of folly is a person that talks a lot. A sign for ignorance is a person that praises himself. One that has all the signs is a fool.
“יְהַלֶּלְךָ זָר וְלֹא פִיךָ נָכְרִי וְאַל שְׂפָתֶיךָ.”
“Let another praise you, and not your own mouth; A stranger, and not your own lips.”
The logic may be understood as if there’s no one to praise you then you can praise yourself. The Zohar negate this logic and say that if no one recognize a person’s qualities then he can open his mouth only with words of Torah that reveals truth and wisdom. Then people would know the person, his wisdom and praise him accordingly.
There’s nothing in the world that can reveal the nature of a person like the words coming out of his mouth.
The evil Balaam was praising himself on everything he does, exaggerating on the little things and telling truth about the impure actions he did. He was using unclear words to big looked as if he is the greatest prophet in the world. We read how Balaam describes himself in Numbers 24:16
“נְאֻם, שֹׁמֵעַ אִמְרֵי-אֵל, וְיֹדֵעַ, דַּעַת עֶלְיוֹן; מַחֲזֵה שַׁדַּי יֶחֱזֶה, נֹפֵל וּגְלוּי עֵינָיִם.”
“The oracle of him who hears the words of God, And knows the knowledge of the Most High, Who sees the vision of the Almighty, Falling down, and eyes uncovered.”
When we hear a person speaks, we can tap into his thoughts. Every word comes from the mind and with connection to the heart, the lungs vibrate and produce the sound. The actual words reveal the thoughts of a person and the sound reveals the intensity and the energy that carries the words/thoughts. Written words can also tell a lot about the person, but they can be calculated and fake.
Learning to listen to others and understand where they come from, would open for us better communication channels and achieve positive outcomes.