金光明經文句記 1.54

1.54

二、「摩」下，明同。通談幻有，當體即空，不異名如；即空之真能含中道，不同三藏析空定淺，故理名是。通教必通別圓二教，故文標云摩訶衍也。

Second, from "Mo..." (Mahāyāna) onward, clarifying identity. The Shared Teaching discusses illusory existence, which in its very essence is empty; being non-different is called 'thus'. The ultimate [truth] that is identical with emptiness can contain the Middle Way, unlike the analytic emptiness of the Tripiṭaka [Teaching] which is definitively shallow; hence the principle is called 'right'. The Shared Teaching necessarily connects to the Distinct and Perfect teachings; hence the text marks it as 'Mahāyāna'.