Often time people do not care what they speak, many people speak lack, failure, stagnation in their life. Not realizing their words create a life around them. Therefore they begin to live according to the fruit of their lips.
The verse shows us that God will create the fruit of your lips, if your lips bear praise he will bring you to that fruit, but if your lips carry death he will bring death upon you.
This is why it is important to educate your tongue, to speak such as you are willing to receive. I know many people who live a miserable life because they did not mind their tongue, your life is not different from your tongue.
Prophetic Declarations
Father I thank you for the life you have given me, for you have taught my tongue to speak according to your will. AMEN