Supreme Master Ching Hai's Book ”Secrets to Effortless Spiritual Practice,” Pages 174-199, Part 1 of 2

As long as we’re in the material world, every material thing affects us. That’s why we must take care to eat pure foods, foods that have less karmic burden, that have less suffering for our own sake. There are differences between people, not only between Master and disciples. Therefore, I’ve taught you to be frugal, not to be greedy and exceed your share. Do not spend more than you have. When it’s necessary, you can take and use. When it’s not, try not to. Otherwise we might get in trouble. Sometimes we might get sick, or get an incurable disease.