Speech -- Its power for good or evil:

1. Idle pursuits and abusive, slanderous language bring one to poverty. The remedy is to give charity to Torah scholars: this brings wealth (4:8).
2. The way to study Torah is by speaking the words out loud. The words will then become a light which will illuminate for you all the places where you must repent and make amends. Eventually you will achieve perfect repentance, and then you will come to understand the very depths of Torah (11:1).
3. You must strive to sanctify the way you speak until your words are the words of the `Holy Tongue.' Speak many words of Torah. Say many prayers and make many entreaties before God. Talk to Him; plead with Him. And at the same time be careful to avoid any falsehood and derogatory comments about other people. If you are careful about the way you speak it will help you to achieve personal sanctity and to guard the Holy Covenant. And the more you purify and sanctify yourself the more you will be able to perfect the way you speak (19:3).
4. Words which are neither listened to nor accepted cannot be called `speech' at all. The way to discover the true meaning of the gift of speech is through speaking the praises of the Tzadikim. This is the complete tikkun for speech (29:1,2).
5. Speech is the vessel with which we receive the flow of blessings. According to the words, so is the blessing. One who attains perfection in the way he speaks, can receive abundant blessings by means of the vessels formed by his words. This is the reason why when we pray, we must actually pronounce the words with our lips (34:3).
6. Speech is the breath of the lips of the Holy One, blessed-be-He. To abuse it is to make it into a wild blast, the `raging stormwind' (Psalms 148:8). This `raging stormwind' is the `great accuser,' the source of all the trials and challenges which confront man. This wild spirit wastes away man's very flesh. It is the root of all the slander and falsehood and evil which people speak about each other. It is called the `end of all flesh' (Genesis 6:13) because it works for the destruction of man's flesh and life. All this comes from abusing the faculty of speech (38:2).
7. It is a great thing if you persevere in learning Torah in spite of poverty or other trials and pressures and difficulties. This is the way to achieve perfection in your speech. A thread of lovingkindness will be drawn down over you (Chagigah 12b) and the forces of stern justice and impurity ranged against you will be thrust aside. Your speech will become cleansed and elevated. The words will flow out in song and praise to God, you will pray with strength and fire, and your heart will be aroused to serve God with true devotion. In the end you will be worthy of speaking the pure truth before God, the truth in your heart will flow forth, and you will be filled with a fiery passion to return to God (Ibid. 4-5).
8. Empty words devoid of holiness give strength to the temples of idolatry. The hand of falsehood is strengthened and the exile deepens. All contact with the spirituality of the Land of Israel becomes lost. Truth is concealed, divisiveness and strife multiply. The Shechinah is locked in strife with her children, exiled as they are from their land and the table of their Father. But words of holiness put strength into the hand of Truth (45).
9. Talking in a derogatory way about other people reinforces the power of fantasy and illusion within us. When people use bad language and speak derogatorily about others, their Da'at, understanding, is taken from them and they fall from the love of God into animalistic passions and desires. The source of these passions and desires is in the faculty of fantasy and imagination, which is part of man's animal nature. It feeds upon falsehood and slander. It is directly opposed to the faculty of memory, through which we keep the true facts of our situation and our eternal destiny in the forefront of our minds. Those who abuse language fall instead into `forgetfulness,' which is `death to the heart' because their heart dies within them and they never remember that the true goal of our life in this world is the eternal life of the World to Come. People like this are dead even in their lifetime, because they have no conception of their true goal and purpose (54:5).
10. Excessive greed for food and drink causes speech to go into `exile.' The words become trapped in the constriction of the throat. One who is a glutton is unable to say a single word before God. The remedy for this is fasting (62:5).
11. There are many different kinds of degenerate speech: talking unfairly and untruthfully about other people; telling people what their friends and acquaintances said about them or did to their disadvantage; telling lies; cynicism and sarcasm; flattery; embarrassing people publicly; obscene talk; unnecessary remarks and so on. Worst of all is when people cast aspersions on the Tzadikim and on those who are honest and God-fearing. Talk like this gives wings to the primordial serpent. It flies through the world wreaking havoc. This `serpent' is the sophistry of the philosophers and other apostles of atheism. Today this has spread throughout the world and is gaining ever-increasing prestige and power. But words of holiness form wings for the domain of the holy (63).
12. You must struggle until you are serving God with every drop of blood you possess. You must speak many words of Torah and prayer until all the blood within you is transformed into these holy words. Then you will find peace, and the spirit of strife and contention will be broken. For contention and rivalry have their source in the drops of blood with which a person has not yet served God (75).
13. Words of Torah and prayer have the power to raise up the fallen sparks and restore and renew all the fallen worlds. The one who speaks them is accounted as if he had created Heaven and Earth and all the worlds afresh. We must speak only words of holiness and nothing else. Then the sparks will be raised up, the worlds will be restored, and Mashiach will come (Ibid.).
14. You must speak words of Torah and prayer to the point where your body becomes totally nullified, as if it literally did not exist. To achieve this you must develop true awe of Heaven. This will bring you peace and harmony, and the world will be filled with blessing (Ibid.).
15. Words of holiness -- Torah and prayer -- are a very high concept. Holy words are the Shechinah, the Divine Indwelling, because the kingship of God and the truth of His existence is revealed through them. Holy speech is the `breath of Mashiach.' It is ruach hakodesh, the Holy Spirit, and it includes the concepts of the revival of the dead and of the unification of the Holy One, blessed-be-He, and the Shechinah (78).
16. Speech is a `mother of children' (Psalms 113:9). Just as a mother always stays with her child and never forgets him even if he goes to the filthiest of places, so the power of speech never leaves a person even if he finds himself in the filthiest of places. Even one who is sunk in the lowest of levels can always remind himself of God's presence if he speaks words of holiness: Torah and prayer. Regardless of his situation, he should make an effort to speak words of Torah and prayer, to meditate and speak to God, and to discuss religious matters with his teacher and his friends. Then he will always be able to remind himself of God's presence regardless of how far he may be from God, even if he falls to the `filthy places.' The faculty of speech will never desert him, and he will never be able to forget God. Understand the tremendous power of speech. This idea can save you from destruction (Ibid.).
17. Speech derives from the Divine aspect of Gevurah, which denotes strength and severity. Therefore all speech must be sweetened through studying Torah and speaking words of goodness and holiness. This is the reason why we must be so careful to avoid any form of degenerate speech, especially derogatory comments about other people. More than anything else this applies to the way we talk about the Tzaddik. To cast aspersions upon the Tzaddik arouses the force of severity in the world, and can cause the Tzaddik to fall from his level if he lacks sufficient force to sweeten it. He may even die because of this, and then the harsh forces are sweetened by the departure of his soul from the world.
18. When a person sits down and starts discussing somebody else it is a `day of judgement,' for he is in effect sitting in judgement on his neighbor. You must be very careful about this. Take a good look at yourself and ask if you are worthy to pass judgement on your friend. Judgement belongs to God, as our Rabbis said: `Do not judge your neighbor until you come into his place' (Avoth 2:5). Who really knows the place of his neighbor and who can come there aside from God alone? (Likutey Moharan II, 1:14).
19. Trust is the foundation of perfect speech: when we acknowledge God, praise Him and learn His law, all the lines of truth spread their radiance throughout the different aspects of speech and bring it to perfection (2).
20. Speech has tremendous power. Speak many words of Torah, say many prayers, and make all kinds of appeals and entreaties to God. More than anything else, talk to God in your own words. If you are determined and make a practice of this every day of your life, you will certainly attain the ultimate good both in this world and in the World to Come.