Venerable Xuyun
(Patriarch of five lineages of Chinese Buddhism)
Of the three types of karma (of body, speech and mind), the mind-related karmas are extremely heavy and most consequential. All virtues or non-virtues start from the mind. If the thought is virtuous, then it becomes the ten virtues (of body, speech and mind). If the thought is non-virtuous then it becomes the ten non-virtues.
The Dharma path is training precisely this mind. A Dharma practitioner practices this mind. The Chan meditator investigates this mind. The Amitabha pureland practitioner recites with this mind. In all interactions with others, in all good or bad circumstances, subdue this mind.
When mingling with people, have a gentle mind. When managing wealth, have a pure and honest mind. In handling matters, have a sincere and loyal mind. When managing subordinates, have a magnanimous and open mind.
Treat others with a fair mind. Distribute gifts with an equal mind. At all places and times, cultivate, refine and control this mind so that it doesn’t become wild, undisciplined, extreme, egoistic or arrogant.
Even the slightest impurity left untouched in the mind is a demonic obstacle that doesn’t benefit you—one should not practice the Dharma this way.