Taittirīya Upaniṣad
ब्रह्मविदाप्नोति परम्। सत्यं ज्ञानमनन्तं ब्रह्मा।
Part of the Yajus Śākhā, this Upaniṣad consists of 3 sections. The first one is the Śīkṣāvallī which summarises ways to lead a meaningful life. The next 2 sections help meaningfully contemplate the Para-Brahman with different methods and techniques. The second section i.e. the Brahmāndandavallī is designed for a logically minded seeker. This section also explains the contemplative creation of the universe. The third one is the Bṛguvallī designed for a creative mind.