Verse
धूमो रात्रिस्तथा कृष्णः षण्मासा दक्षिणायनम् ।तत्र चान्द्रमसं ज्योतिर् योगी प्राप्य निवर्तते ॥
dhūmo rātristathā kṛṣṇaḥ ṣaṇmāsā dakṣiṇāyanamtatra cāndramasaṃ jyotir yogī prāpya nivartate
Fire and light and smoke or mist, the day and the night, the bright fortnight of the lunar month and the dark, the northern solstice and the southern, these are the opposites. By the first in each pair the knowers of the Brahman go to the Brahman; but by the second the Yogin reaches the “lunar light” and returns subsequently to human birth.
Gītā 8·25