These eight, viz., water, roots, fruits, milk, clarified butter (what is done at) the desire of a Brahmana, (or at) the command of a preceptor, and medicine, are not destructive of a vow. That which is antagonistic to one’s own self, should never be applied in respect of another. Briefly even this is virtue. Other kinds of virtue there are, but these proceed from caprice.

In plain words: Eight things do not break a religious fast or vow: water, roots, fruit, milk, ghee (clarified butter), something done at a priest's request, something done at a teacher's command, and medicine. In short, the heart of goodness is this: don't do to others what you would not want done to you.