Sangitisutta 1.5.7

1.5.7

Atha kho bhagavā catugguṇaṃ saṅghāṭiṃ paññāpetvā dakkhiṇena passena sīhaseyyaṃ kappesi pāde pādaṃ accādhāya, sato sampajāno uṭṭhānasaññaṃ manasi karitvā.

And then the Buddha spread out his outer robe folded in four and laid down in the lion’s posture—on the right side, placing one foot on top of the other—mindful and aware, and focused on the time of getting up.