The oldest surviving systematic exposition of yoga philosophy, the Pātañjala Yogaśāstra (ca. fourth century CE), is composed of two different layers of text. The first layer consists of brief phrases, so-called sūtras which probably are at least in part a compilation of older textual materials. Within the Pātañjala Yogaśāstra (PYŚ), the sūtras frequently serve as starting points for more detailed discussions of relevant topics in the second layer, the so-called bhāṣya. Accordingly, the sūtra and bhāṣya-passages of the PYŚ form a unified whole that is the result of the single intention of a compiler and author named Patañjali. In the present paper, I take a fresh look at the exposition of posture as an ancillary of yoga in PYŚ 2.46-48. This passage contains the famous characterization of posture as sthirasukham, which was understood in various ways by the Sanskrit-commentators and by modern scholars and translators. By weighting these interpretations against each other and by drawing upon different textual versions of the passage under discussion as they are transmitted partly in unpublished manuscripts, I hope to arrive at an improved understanding of Patañjali’s conceptions of what postures are, how they are achieved and which purposes they serve.