Taittiriya Upanishad 2.8.1

2.8.1

bhīṣā 'smādvātaḥ pavate /
bhīṣodeti sūryaḥ /
bhīṣā 'smādagniścendraśca /
mṛtyurdhāvati pañcama iti /
saiṣā ' 'nandasya mīmām̐sā bhavati /
yuvā syātsādhuyuvā 'dhyāyakaḥ /
āśiṣṭho dṛḍhiṣṭho baliṣṭhaḥ /
tasyeyaṃ pṛthivī sarvā vittasya pūrṇā syāt /
sa eko mānuṣa ānandaḥ /
te ye śataṃ mānuṣā ānandāḥ // 1//

Out of His fear the Wind blows. Out of fear the Sun rises. Out of His fear runs Fire, as also Indra, and Death, the fifth.

This, then, is an evaluation of that Bliss:

Suppose there is a young man—in the prime of life, good, learned, most expeditious, most strongly built, and most energetic. Suppose there lies this earth for him filled with wealth. This will be one unit of human joy.footnote{A unit of measurement for the estimation of Bliss.} If this human joy be multiplied a hundred times, it is one joy of the man-Gandharvas, and so also of a follower of the Vedas unaffected by desires. If this joy of the man-Gandharvas be multiplied a hundred times, it is one joy of the divine-Gandharvas, and so also of a follower of the Vedas unaffected by desire. If the joy of the divine-Gandharvas be increased a hundredfold, it is one joy of the manes whose world is everlasting, and so of a follower of the Vedas untouched by desire. If the joy of the manes that dwell in the everlasting world be increased a hundredfold, it is one joy of those that are born as gods in heaven, and so of a follower of the Vedas untouched by desire. If the joy of those that are born as gods in heaven be multiplied a hundredfold, it is one joy of the gods called the Karma-Devas, who reach the gods through Vedic rites, and so of a follower of the Vedas unaffected by desire. If the joy of the gods, called the Karma-Devas, be multiplied a hundredfold, it is one joy of the gods, and so of a follower of the Vedas untarnished by desire. If the joy of the gods be increased a hundred times, it is one joy of Indra, and so of a follower of the Vedas untouched by desire. If the joy of Indra be multiplied a hundredfold, it is one joy of Bṛhaspati and so of a follower of the Vedas unaffected by desire. If the joy of Bṛhaspati be increased a hundred times, it is one joy of Virāṭ, and so of a follower of the Vedas untarnished by desire. If the joy of Virāṭ be multiplied a hundred times, it is one joy of Hiraṇyagarbha, and so is it of the follower of the Vedas unsullied by desire.