MUṆḌAKA UPANISHAD · 2.2.6

अरा इव रथनाभौ संहता यत्र नाड्यः ।
स एषोऽन्तश्चरते बहुधा जायमानः ।
ओमित्येवं ध्यायथ आत्मानं स्वस्ति वः
पाराय तमसः परस्तात् ॥ ६॥

arā iva rathanābhau saṃhatā yatra nāḍyaḥ ।
sa eṣo’ntaścarate bahudhā jāyamānaḥ ।
omityevaṃ dhyāyatha ātmānaṃ svasti vaḥ
pārāya tamasaḥ parastāt ॥ 6॥

Where the nerves are brought close together like the spokes in the nave of a chariot-wheel, this is He that moves within, — there is He manifoldly born. Meditate on the Self as OM and happy be your passage to the other shore beyond the darkness.

Sri Aurobindo · CWSA 18, p. 140