Sighing:

1. The sighs and groans of a Jew are very precious. When a person is lacking something, sighing and groaning can bring wholeness and completeness. But only if he is close to the Tzaddik who is the guide and leader of the age. The breath of the sigh is drawn from the breath of life with which God created the world. When a thing is incomplete, it is really lacking in life-force - the breath of life which keeps it in existence. When a person breathes long and deep, he draws new life. But the breath of life is in the Torah. The Tzaddik is totally bound to the Torah. Therefore the breath of life is with the Tzaddik. From him we can draw the breath of life for our groans and sighs, and bring wholeness and completeness where before they were missing (8:1,2).
2. A person may be praying with great devotion or at the height of meditation and then suddenly in the middle he falls from his level. It is a sign that there is some flaw in his faith. He should feel broken and ashamed. How could he fall from heaven to earth? He should arouse tender pity for himself to the point where he literally sighs. This sigh will bring him back to his level (108).
3. How precious when you sigh out of longing for something holy. The sigh you let out because you are far from holiness breaks the bond of impurity which was trapping you. Now you can bind yourself with the cord of holiness. But the opposite is true when you sigh with desire for something wrongful, God forbid (109).
4. One sigh of regret for your sins and the distance which separates you from God is worth more than many fasts and other forms of selfmortification. The sighs you let out when you want something holy can actually break the force of your bodily instincts. Then the soul can draw nearer to the body and communicate to it something of her own perception of God (Ibid.).