शुक्लकृष्णे गती ह्येते जगतः शाश्वते मते। एकया यात्यनावृत्तिमन्ययाऽऽवर्तते पुनः ॥

śhukla-kṛiṣhṇe gatī hyete jagataḥ śhāśhvate mate ekayā yātyanāvṛittim anyayāvartate punaḥ

Light and darkness, these are thought to be the world's everlasting paths; by the one he goeth who returneth not, by the other he who returneth again.

In plain words: Light and darkness are the two lasting paths of the world. One leads to freedom with no return. The other leads back to birth again.