sthirasukham āsanam [YS 2.46]

tadyathā padmāsanaṃ bhadrāsanaṃ svastikaṃ daṇḍāsanaṃ sopāśrayaṃ paryaṅkaṃ krauñcaniṣadanaṃ hastiniṣadanam uṣṭraniṣadanaṃ samasaṃsthānaṃ sthirasukhaṃ yathāsukhaṃ cety evamādīni.