Śiva upāsanā mantra is part of the Taittirīya Āraṇyaka. This is the forest treatise (part of the Vedas traditionally learnt in the forest region) of the Yajur Veda. It occurs in the 10th Praśna, Anuvākas 16-25. It also comes as a portion in the Mahānārāyaṇa Upaniṣad, Yajur Veda.
