Upanishads · Praśna 1.12
॥
Devanāgarī
मासो वै प्रजापतिः ।
तस्य कृष्णपक्ष एव रयिः शुक्लः प्राणः ।
तस्माद् एत ऋषयः शुक्ल इष्टं कुर्वन्तीतर इतरस्मिन्
Transliteration (IAST)
māso vai prajāpatiḥ |
tasya kṛṣṇapakṣa eva rayiḥ śuklaḥ prāṇaḥ |
tasmād eta ṛṣayaḥ śukla iṣṭaṃ kurvantītara itarasmin
Word-by-word
SanskritIASTMeaning
मासः वैmāsaḥ vaithe month indeed; the lunar month
प्रजापतिःprajāpatiḥPrajāpati; the lord of creatures
तस्यtasyait; in It
कृष्णपक्षः एवkṛṣṇapakṣaḥ evathe dark half [of the month] (kṛṣṇa-pakṣa); the waning fortnight; the black fortnight
रयिःrayiḥrayi; the material-nourishing principle
शुक्लःśuklaḥthe bright [half] (śukla); the waxing fortnight; the white fortnight
प्राणःprāṇaḥthe prāṇa; the vital principle
तस्मात्tasmāttherefore; for that reason
एते ऋषयःete ṛṣayaḥthese seers; such sages
शुक्लेśuklein the bright fortnight; in the waxing moon
इष्टम् कुर्वन्तिiṣṭam kurvantithe sacrifice (iṣṭa); the sacrificial act; the rite
इतरेitareother; the rest
इतरस्मिन्itarasminin the other; in the dark fortnight
Translation
"The month indeed is Prajāpati: its dark half is rayi, its bright half prāṇa. Therefore some seers offer sacrifice in the bright [half], others in the other."
Version
c3126f28a245 · published Jul 26, 2026, 8:35:21 PM UTC
Available inRUENPage between verses with
The same pattern on a smaller circle: māso vai prajāpatiḥ — "the month is Prajāpati". The lunar month falls into two: kṛṣṇa-pakṣa, the dark half of the waning moon, is rayi, storing and nourishment; śukla-pakṣa, the bright half of the waxing, is prāṇa, life and ascent. Year, month — and in the next verse the day: time is self-similar as a crystal: at every scale the same two, substance and life, in eternal alternation.
tasmād eta ṛṣayaḥ śukla iṣṭaṁ kurvanti — "therefore these seers sacrifice in the bright half, others in the other": practice is attuned to the rhythm. The knowing align the rites of ascent with the waxing moon, and those addressed to the fathers with the waning; not superstition but literacy: an act set into a favouring wave of time is carried further.
Behind this "calendar science" lies the general law for whose sake it is told: time is not neutral. Every portion of it is coloured — toward life or toward substance, toward ascent or toward accumulation — and one who honours those colours lives with the breathing of Prajāpati, not athwart it.