Saint Isaac said: “the fasting of the tongue is better than the fasting of the mouth, and the abstinence of the heart from lust is better than both fasts”.
Many people concern themselves with abstaining from food. God rebuked them, saying: “Not what goes into the mouth defiles a man; but what comes out of the mouth, this defiles a man.” (Matt 15:11). This way, He shows us that bad-talk is defiling. Therefore, our teacher, the Apostle James, refers to the tongue which “defiles the whole body.” (James 3:6). Is your tongue, thus, fasting with the rest of your body? And is your heart abstaining from lusts?
A fasting heart is able to make the tongue fast with it, for “out of the abundance of the heart the mouth speaks.” (Matt 12:34).
The Lord also said, “But those things which proceed out of the mouth come from the heart, and they defile a man. “ (Matt 15:18). Moreover, “A good man out of the good treasure of his heart brings forth good things, and an evil man out of the evil treasure brings forth evil things.” (Matt 12:35). Therefore, if your heart abstains from sin, your tongue will abstain from every idle word.
He who has a fasting heart, can also make his body fast also.
Therefore, what is important is for the heart and thought to abstain from every wrong desire assisted by the fasting of the body, which is the least of all, Therefore, in your fast, control your tongue. As you make your mouth refrain from food, also make it refrain from bad words. Increase your control over your thoughts and your reactions.
Overpowering the body is not an aim in itself but rather a vehicle for the soul.
Overpowering the body is necessary lest it should digress and cause the soul to perish. In this regard, the apostle says in earnest, “But I discipline my body and bring it into subjection, lest, when I have preached to others, I myself should become disqualified.” (1 Cor 9:27). When the body is subdued, the soul takes control and the body stop resisting, start collaborating with it and submitting to its leadership.
Therefore, control your body and keep it wisely from all futile enjoyment, luxury, and lust.
It is not enough that you fast, for you also need to overcome the lust for food.