大毘盧遮那成佛經疏 2.73

2.73

第四十四「云何火心？謂熾盛炎熱為性」者，如火性赫奕躁疾。此人心亦爾，若造善時須臾間能成無量功德，造惡亦少時成極重業。此中治行，應思惟猛暴之心多所敗傷，以柔和慈善之水方便令滅，而熾然善事務令恒久，是彼對治。

The forty-fourth: "What is the fire mind? It is having blazing heat as its nature." Just as the nature of fire is brilliant and impetuous; this person's mind is also like this: when creating good, in an instant it can accomplish immeasurable merit; when creating evil, in a brief moment it also accomplishes extremely heavy karma. The counteracting practice here is: one should reflect that a fierce and violent mind causes much ruin and injury, and extinguish it through expedients with the water of gentleness and loving-kindness, while ensuring that the blazing of wholesome deeds is made constant; this serves as its antidote.