तैत्तिरीय आरण्यकं वनेषु अध्येतव्याः रहस्यात्मकाः शिक्षाः समाविशति। अस्मिन् उपनिषदः, ध्यानविधयः, आत्मज्ञानं च निरूपितम्।

The Taittiriya Aranyaka contains esoteric teachings meant to be studied in forests. It includes the famous Taittiriya Upanishad, meditation techniques, and knowledge of the Self. Prapatakas 7-9 contain the Taittiriya Upanishad with its teachings on Brahman and the five sheaths.