The Jātavedas hidden in the two pieces of arani wood, like a fetus well protected by pregnant women — Agni, adorable each day by the wakeful, by humans who offer oblations. This is in truth That.

This verse uses the metaphor of sacrificial fire to describe the Ātman.

Araṇyor nihitaḥ — hidden in the two pieces of arani wood. The araṇi wood pieces used to generate fire by friction.

Jātavedāḥ — the one who knows all the born. Epithet of Agni, the fire god.

Garbha iva subhṛtaḥ garbhiṇībhiḥ — like a fetus well protected by pregnant women. The Ātman is hidden but cared for.

Dive dive īḍyaḥ — adorable each day. The constant worship.

Jāgṛvadbhir haviṣmadbhir manuṣyebhir agniḥ — Agni [adored] by the wakeful, by humans who offer oblations.

Etad vai tat — this is in truth That.

The metaphor indicates that the Ātman requires effort (tapas, spiritual friction) to be revealed.