In plain words
Pradoṣe dīpakaś candraḥ prabhāte dīpako raviḥ. Trailokye dīpako dharmaḥ suputraḥ kuladīpakaḥ.
Students!
The moon gives light through the hours of night. Through the hours of day, the sun brings light and radiance and gives them out. For the three worlds, Dharma brings light and radiance. A good son lights the lamp of his family.
You know the difference between the new-moon night and the full moon. The new-moon night is a dreadful night, pitch dark. Good-hearted people do not want this darkness in the least. Darkness is fearful. Not fear alone. It breeds evil thoughts. Not evil thoughts alone: it leads into evil deeds. Darkness torments man in many ways, through many wicked resolves, through evil thoughts, through evil feelings and through evil deeds. The wicked, the evil-minded and the arrogant alone long for this darkness; no good-hearted person longs for it. To thieves, to the wicked and to the evil-minded, darkness is a great help. They long for this darkness itself. Darkness helps them a great deal in carrying out the deeds they have resolved on. So only people of evil resolve long for darkness.
People of good resolve, rich in good conduct and in good deeds, long for light alone. At the sight of moonlight, man's heart grows cool and, in a calm mood, along the right path, fosters good resolves. Even little children are so happy to see the moonlight. In this cool moonlight, poets weave into poetry the good feelings that rise from the heart. On the full-moon day, man's heart is full. We must also enquire well into the kinship between man's mind and the full moon. The moon is the very reflection of the mind. In the moon's light, man's mind grows cool, with good feelings and good resolves. The full moon drives away darkness, removes ignorance, removes fear too, and fosters peace and security, joy and good resolves.