In plain words
You all know: the great philosopher … Sidney, when he was a small boy, used to study as a student in another village. His father wrote him a fine letter. My son! Pray to God from your heart, every day. Make the effort needed to bring your Manas to the divine presence of God. With your fellow students and with your teachers, conduct yourself with humility and obedience. Give no room to anger, to despair or to dejection. If anyone abuses you, do not be cast down. If anyone praises you, do not swell up. Do not abuse others. But at the very end he wrote one sentence. If you have to make a promise, make no promise to anyone but God alone. Speech is the sound of God; make no promise to others, to none but God alone. You have no right even to make one. You become one who has misused your speech. Only then will your brilliance shine. Your sense of discrimination will grow. You will become an ideal student in society. So keep your tongue under control. At no time at all let it run loose. Sidney, who took that command upon his head, grew into a great philosopher. For students, too much talk does harm to the mind. Students must not go into any matters at all other than matters of learning. You have come in as a seeker of learning, not as a seeker of worldly things. After you have gained complete learning, you may enter into worldly matters. Even then you may move among them in a measured way. So do not let this tongue run into too much talk.
The tongue keeps committing four kinds of sin. 1. Speaking Asatya. 2. Telling tales. 3. Speaking ill of others. 4. Talking too much. It is through these four that unrest grows in humanity. Ill health too comes of them. So within humanness we must try to speak only this Satya: 'Speak Satya; practise Dharma.' At some times, telling Satya becomes a little dangerous. At such times, no Satya and no Asatya. Only when you follow a path like this do you become one who has nourished humanness well in society. These senses are mighty and powerful. These senses alone are the chief cause of all pleasures and sorrows.