大毘盧遮那成佛經疏 2.63

2.63

第卅四「云何擊鼓心？謂修順是法，我當擊法鼓」者，鼓能警誡眾生，令得覺悟。若行人作如是念：「眾生長夜昏寢，我當習種種無礙辨才，擊大法鼓而警悟之。」亦能妨礙淨心也。當念早證無量語言陀羅尼，以天鼓妙音普告一切眾，勿以世間小利妨大事因緣，是彼對治。

The thirty-fourth: "What is the drum-beating mind? It is following the practice of this teaching [thinking]: 'I shall beat the drum of the Dharma.'" A drum can sound an alarm to sentient beings, bringing them to awakening. If a practitioner thinks: "Sentient beings sleep in the stupor of the long night; I shall master various unhindered eloquence to beat the great drum of the Dharma and awaken them," this too can obstruct the pure mind. Reflecting: "I must swiftly realize the dhāraṇī of immeasurable tongues and announce this universally to all assemblies with the wondrous sound of the celestial drum, without letting small worldly benefits obstruct this great matter of causation," serves as its antidote.