PRAŚNA UPANISHAD · 1.10

अथोत्तरेण तपसा ब्रह्मचर्येण श्रद्धया
विद्ययाऽऽत्मानमन्विष्यादित्यमभिजयन्ते । एतद्वै
प्राणानामायतनमेतदमृतमभयमेतत् परायणमेतस्मान्न पुनरावर्तन्त
इत्येष निरोधस्तदेष श्लोकः ॥ १.१०॥

athottareṇa tapasā brahmacaryeṇa śraddhayā
vidyayā’’tmānamanviṣyādityamabhijayante । etadvai
prāṇānāmāyatanametadamṛtamabhayametat parāyaṇametasmānna punarāvartanta
ityeṣa nirodhastadeṣa ślokaḥ ॥ 1.10॥

“But by the way of the northern solstice go the souls that have sought the Spirit through holiness and knowledge and faith and askesis; for they conquer their heavens of the Sun. There is the resting place of the breaths, there immortality casteth out fear, there is the highest heaven of spirits; thence no soul returneth; therefore is the wall and barrier. Whereof this is the Scripture.

Sri Aurobindo · CWSA 18, p. 178