ŚVETĀŚVATARA UPANISHAD · 2.11

नीहारधूमार्कानलानिलानां खद्योतविद्युत्स्फटिकाशशीनाम् ।
एतानि रूपाणि पुरःसराणि ब्रह्मण्य् अभिव्यक्तिकराणि योगे ॥

nīhāradhūmārkānalānilānāṃ khadyotavidyutsphaṭikāśaśīnām ।
etāni rūpāṇi puraḥsarāṇi brahmaṇy abhivyaktikarāṇi yoge ॥

When Yoga is being performed, the forms which come first, producing apparitions in Brahman, are those of misty smoke, sun, fire, wind, fire-flies, lightnings, and a crystal moon.