PRAŚNA UPANISHAD · 3.6

हृदि ह्येष आत्मा । अत्रैतदेकशतं नाडीनां तासां शतं
शतमेकैकस्या द्वासप्ततिर्द्वासप्ततिः प्रतिशाखानाडीसहस्राणि
भवन्त्यासु व्यानश्चरति ॥ ३.६॥

hṛdi hyeṣa ātmā । atraitadekaśataṃ nāḍīnāṃ tāsāṃ śataṃ
śatamekaikasyā dvāsaptatirdvāsaptatiḥ pratiśākhānāḍīsahasrāṇi
bhavantyāsu vyānaścarati ॥ 3.6॥

“The Spirit in the heart abideth, and in the heart there are one hundred and one nerves, and each nerve hath a hundred branch-nerves and each branch-nerve hath seventy two thousand sub-branch-nerves; through these the breath pervasor moveth.

Sri Aurobindo · CWSA 18, p. 183