大毘盧遮那成佛經疏 3.42

3.42

次有五偈，明其勸發方便。初偈云「佛子此大乘，真言行道法，我今正開演，為彼大乘器」者，意言：汝佛子當知，今此大乘真言行所乘之道法則儀軌，以汝是大乘器量故堪能信受，我今當正說之也。

Next are five verses explaining the upāya of exhortation. The first verse says: / "Son of the Buddha, this Great Vehicle, / The path and method of mantra practice, / I now properly expound / For that vessel of the Great Vehicle": / the meaning is: You, son of the Buddha, should know that the path, method, and ritual of this Great Vehicle practice of mantras, because you have the capacity of a vessel of the Great Vehicle and are able to faithfully accept it, I shall now properly expound.