"This slogan is connected with the postmeditation experience which comes after the main practice. Relating to passion, aggression, and ignorance in the main practice of tonglen* is very intense, but the postmeditation practice is somewhat lighter.
*tonglen: "Sending and taking is a very important practice of the bodhisattva path. It is called tonglen in Tibetan: tong means "sending out" or "letting go," and len means "receiving," or "accepting." Tonglen is a very important term; you should remember it. It is the main practice in the development of relative bodhichitta.
"These two should ride the breath."
The practice of tonglen is quite straightforward; it is an actual sitting meditation practice. You give away your happiness, your pleasure, anything that feels good. All of that goes out with the outbreath. As you breathe in, you breathe in any resentments and problems, anything that feels bad. The whole point is to remove territoriality altogether."
The three objects are friends, enemies, and neutrals. The three poisons are passion, aggression, and ignorance or delusion. And the three seeds of virtue are the absence of passion, aggression, and ignorance.
The practice of this slogan is to take the passion, aggression, and delusion of others upon ourselves so that they may be free and undefiled. Passion is wanting to magnetize or possess; aggression is wanting to reject, attack, cast out; and ignorance or indifference is that you couldn't be bothered, you are not interested, a kind of anti-prajna energy. We take upon ourselves the aggression of our enemies, the passion of our friends, and the indifference of neutrals.
When we reflect on our enemy, that inspires aggression. Whatever aggression our enemy has provided for us - let that aggression be ours and let the enemy thereby be free from any kind of aggression. Whatever passion has been created by our friends, let us take that neurosis into ourselves and let our friends be freed from passion. And the indifference of those who are in the middle or unconcerned, those who are ignorant, deluded, or noncaring, let us bring that neurosis into ourselves and let those people be free from ignorance.
Whenever any of the three poisons happens in your life, you should do the sending and taking practice [tonglen]. You just look at your passion, your aggression, and your delusion - you do not regard them as a problem or as a promise. Instead, when you are in a state of aggression, you say: "May this aggression be a working base for me. May I learn to hold my aggression to myself, and may all sentient beings thereby attain freedom from aggression." Or: "May this passion be mine. Because it belongs to me by virtue of my holding on to it, therefore may others be free of such passion." For indifference, you do the same thing.
The purpose of doing that is that when you begin to hold the three poisons as yours, when you possess them fully and completely, when you take charge of them fully, you will find, interestingly enough, that the logic is reversed. If you have no object of aggression, you cannot hold your own aggression purely by yourself. If you have no object of passion, you cannot hold your passion yourself. And in the same way, you cannot hold on to your ignorance either.
By holding your poison, you let go of the object, or the intent, of your poison. You see, what usually happens is that you have objects of the three poisons. When you have an object of aggression, for example, you feel angry toward it - right? But if your anger is not directed toward something, the object of aggression falls apart. It is impossible to have an object of anger, because the anger belongs to you rather than to its object. You give your compassion to the object so that it doesn't provoke your anger - then what are you angry with? You find yourself just hanging out there, with no one to project onto. Therefore, you can cut the root of the three poisons by dealing with others rather than by dealing with yourself. So an interesting twist takes place."
It is important to know that we are responsible for our own "poisons." Our emotions and reactions are our own. Other people may do things, circumstances may occur but the phrase "So and so made me so angry!" is not true. So and so may be the biggest jackass in the world but no one can "make" us anything. It is important for us, our well-being, our relationships, our view of reality, that we take ownership of our own emotions... the same is true for our expectations, resentments, cravings, desires, attachments, motivations, and delusions.
With this in mind, tonglen practice and an understanding of how the three poisons act in the world... our own personal world... begins to make a great deal of sense and becomes a very powerful tool towards transforming those three poisons in the three seeds of virtue.