Text:

अरण्योर्निहितो जातवेदा गर्भ इव सुभृतो गर्भिणीभिः ।
दिवे दिवे ईड्यो जागृवद्भिर्हविष्मद्भिर्मनुष्येभिरग्निः । एतद्वैतत् ॥ ८ ॥

araṇyornihito jātavedā garbha iva subhṛto garbhiṇībhiḥ |
dive dive īḍyo jāgṛvadbhirhaviṣmadbhirmanuṣyebhiragniḥ | etadvaitat || 8 ||

8. The fire lodged in the aranis, as the foetus is well-borne by the pregnant woman fit to be worshipped every day by watchful offerers and other men. This verily is that.

Shankara’s Commentary:

Again, the sacrificial fire lodged in the upper arani and the lower arani, the eater of all offerings and the fire within the body; which are well-maintained by the ritviks and yogins, respectively, as the foetus is well-maintained in the world by pregnant women, by means of food, drink, etc., not condemned. Moreover, fit to be worshipped, i.e., eulogised and adored every day by those who follow Karma and by those who follow yoga, in sacrifices and at heart; jagrivadbhih, who are by nature on the alert, i.e., watchful. Havishmadbhih, by those having offerings such as ghee, etc., and by those having contemplation and meditation. This verily is that—that Brahman now treated of.