Refrain from doing that which is unsuitable,
cultivate that which is wholesome;
purify the heart.
This is the teaching of the Awakened Ones.
Dhammapada v.183
Although this verse might appear very simple, it can in fact be considered a formula for how to live our whole life. The first line addresses our habits of heedlessness. Just as cooking food in an unhygienic kitchen could cause sickness, so spiritual practice without the skill of restraint is dangerous. The second line points to the need for building up a storehouse of goodness. We wouldn’t aim to climb Mount Everest without the right provisions. Likewise, it is not sensible to aim for freedom from suffering without cultivating a reservoir of wholesomeness from which we can draw strength when needed. These first two lines are about preparing ourselves for the work that is described in the third line: purifying the heart, which involves great heat, great pressure, and a great deal of patience. The fourth line states that this same teaching is given by all the Buddhas.