The mind is like a fertile field. If we contaminate it with the poisons of ignorance, desire, anger, jealousy, and pride, we will inevitably produce poisonous crops. Acting carelessly or harmfully toward others, or working for our own benefit at the expense of others, will only create limitation and suffering. Medicinal seeds — wholesome, virtuous acts of kindness, love, and compassion — will produce the fruits of peace and benefit. Actions that are both positive and negative will produce a mixture of happiness and sadness. This is the principle of karma. Karma originates in the mind. Our thoughts give rise to words and actions, and these have consequences. We cannot plant poisonous seeds and expect edible or medicinal fruit. When we begin to see the negative results of our self-centeredness, we understand why we must carefully choose which seeds to plant. Our future is in our own hands.
(Lama Shenpen Drolma, from Change of Heart: The Bodhisattva Peace Training of Chagdud Tulku)
NKT Poisonous Crops
"We cannot plant poisonous seeds and expect edible or medicinal fruit."