The Mahāvairocana Sūtra, root text of the Garbhadhātu (Womb-World) maṇḍala, gives the famous "three phrases": bodhicitta as cause, compassion as root, skillful means as culmination. This is also the maṇḍala's visual grammar—Mahāvairocana at the center, radiating outward through concentric courts. A maṇḍala ("perfect circle, gathering") is not decoration but a map of reality for contemplation.
The Contemplation Sūtra teaches sixteen visualizations, climaxing in "this very mind is Buddha" (是心是佛). Images are not idols but supports for contemplation: the 32 marks and hand-gestures (mudrās) form a visual grammar the practitioner reconstructs mentally. Dunhuang's vast "Pure Land tableaux" are these sixteen visualizations painted onto walls—a storyboard for meditation, and the seed of Buddhist image-history.
This sūtra tells how King Udayana, longing for the absent Buddha, carved the first human image of him in sandalwood—the "origin myth" of Buddhist iconography. It legitimizes image-making as an act of remembrance (not idolatry) and marks the shift from the aniconic period (Buddha shown only as tree, wheel, footprint, empty throne) to the iconic era of Gandhāra and Mathurā from the 1st–2nd century CE.
The Iconometry Sūtra (translated from Tibetan by mGon-po skyabs, 1742) is the "engineering spec" of image-making: measured in finger-widths (a standing figure = 120 units), it fixes the proportions of every part. A shared Sino-Tibetan canon and the basis of thangka painting, it shows constraint as the precondition of sacred beauty—like a design system letting scattered artisans produce a consistent, recognizable form.