Jñāneśvarī (commentary on the Bhagavadgītā) 4.145

4.145

apāne juhvati prāṇaṃ prāṇe 'pānaṃ tathāpare
prāṇāpānagatī ruddhvā prāṇāyāmaparāyaṇāḥ
maga apānāgnīce mukhīṃ |
prāṇadravyeṃ dekhīṃ |
havana keleṃ ekīṃ |
abhyāsayogeṃ ||

Then, behold, some made an oblation
with the offering of prāṇa
into the mouth of the apāna fire
through the practice of yoga.