首楞嚴義疏注經 8.140

8.140

行願內充，慈悲外發，德相漸成，化物功著，故云表以成人。於十方界次補佛處，堪任付囑，傳法利生，故如國王委政太子陳列灌頂也。

Practices and vows are inwardly abundant, and loving-kindness and compassion manifest outwardly. The marks of virtue are gradually brought to completion, and the merit of converting beings becomes prominent; hence it is said, 'demonstrating that he has come of age.' Succeeding next to the position of a Buddha in the worlds of the ten directions, he is fit to receive the entrustment, to transmit the Dharma, and to benefit living beings; hence it is like a king delegating the governance to the crown prince and arranging the anointing of the crown.