ייִדישער מחשבֿה אויף קהלת 5:5

And in exchange for much talking, substitute prolonged thinking, continuous reflecting, and spiritual accounting (see previous gate), because reflection is a candle which enters your heart, and the spiritual accounting is like the sun which illuminates the darkness of your interior being, to reveal to you what is hidden inside whether of good or of evil.
The tongue is the gate of this inner being. If the tongue is unbridled and does not keep careful guard over what is in the inner being, then the gate to the treasury will be open, and things will go out which you do not wish them to go out, and things will become visible which you do not wish them to be visible. But if you guard the gate, you guard the treasury and what is in it, as the wise man said: "even a fool who keeps silent is considered wise" (Mishlei 17:28). He also said: "do not be quick with your mouth, do not be hasty in your heart to utter anything before G-d" (Koheles 5:1), and: "permit not your mouth to cause your flesh to sin" (Koheles 5:5).