Sandhinirmocana Sutra

The Ārya-saṃdhi-nirmocana-sūtra or Noble sūtra of the Explanation of the Profound Secrets is a Mahāyāna Buddhist text and the most important sutra of the Yogācāra school. It contains explanations of key Yogācāra concepts such as the basis-consciousness, and the doctrine of cognition-only and the "three natures".