Pātañjalayogaśāstravivaraṇa

The 8th century Pātañjalayogaśāstravivaraṇa (Sub-commentary on Patanjali's Yoga Commentary), also called the Yogasūtrabhāṣyavivaraṇa (Sub-commentary on the Commentary on the Yoga Sutras) is Ādi Śaṅkara's commentary on Patanjali's own commentary, the bhāṣya, on his Yoga Sutras. As well as remarking briefly on each sutra, it gives descriptions of the 12 seated asanas named in the bhāṣya, including Dandasana, Svastikasana, and Virasana.

Source: Wikipedia — Pātañjalayogaśāstravivaraṇa (CC BY-SA 4.0)