Tibetan ethnohistories of Buddhist law have traditionally revolved around the figure of the seventh-century emperor Songtsen Gampo, codifier of first written Tibetan law code. This code was putatively “based” on the ten Buddhist virtues, enshrined in early Mahāyāna works such as the Daśabhūmika (“The Ten Grounds”). This claim is often debunked by modern constitutional historians, who argue that there is little evidence of any lineage of Buddhist textual sources from India to Tibet at the time to support such a claim. However, a closer reading of Indian Mahayana texts and subsequent Tibetan writings suggests a different interpretation of this claim: that the emperor’s dependence on the ten virtues was seen to be noetic rather than literary. Specifically, that its formulation was a product of his personal qualities as a second ground bodhisattva, which naturally generated virtuous law in a Buddhist sense; and that it was based on ethical objectives rather than a lineage of codified injunctions. In this sense, the Buddhist core of royal law was understood to depend on the personal virtue and wisdom of the lawmaker, rather than the integrity of the codified textual lineage.