In a way I think we can say that ultimately we see the practice of Buddhism in all of its forms and schools as the practice and implementation of compassion. The ground of all Mahayana is wanting all sentient beings to be free from delusion and suffering. The skillful means to accomplish this is Buddhism.
We insist that true compassion is based upon both logic and reason; by elevating it out of the mere emotional realm we can practice it despite the fact that people are often jerks and even sometimes monsters. We can accept our own deluded nature and that of others and not get “depressed” and thereby avoid falling into hopelessness. Therefore if you ask me how a Mahayana Buddhist implements compassion I must respond by implementing Buddhism in his life.
We call logic and rationality combined with insight gained through meditation wisdom. Often wisdom and compassion seem to conflict. But Zen is paradox and of course paradox is Zen.
To point you to a source for implementing compassion in Mahayana is asking me to point you to virtually everything that has been written on Mahayana because Mahayana is the great compassion. The best book I know on the paradox of practicing both compassion and wisdom is in French but here are some excerpts from it in English.
“Compassion is Mahayana, Mahayana is Compassion’, proclaims the Mahâparinirvâna Sutra. Compassion is the foundation or root of the entire Mahayana edifice. Vimalakîrti’s goddess says she is a Mahâyânist because she never abandons great compassion. It is the defining trait of the bodhisattva. The Abhidharmakosa-bhâsya tells us:
People without compassion and who think only of themselves find it hard to believe in the altruism of the bodhisattvas, but the compassionate believe in it easily. Do we not see that certain people, confirmed in the absence of pity, take pleasure in the suffering of others even when it is of no use to them? In the same way one must admit that the bodhisattvas, confirmed in compassion, take pleasure in doing good to others without any selfish design.”
From Ludovic Viévard’s book, Vacuité (sûnyatâ) et compassion (karunâ) dans le bouddhisme madhyamaka (Collège de France, 2002),
“One may say that ‘wisdom without compassion is empty, compassion without wisdom blind,’ but only rarely do Mahayana texts claim that compassion arises naturally from insight into emptiness. Compassion, directed actively to the welfare of all beings, seems to presuppose their real existence. It is based not on emptiness but on the ‘golden rule’ that treats the sufferings of others as equal to one’s own. Compassion gives a substantial presence to self and other, which wisdom would deny. There is no natural harmony between these two, for they go in opposite directions. Yet the essence of Mahayana lies in establishing the ultimate unity of compassion and wisdom. They are unified in practice in the figure of the bodhisattva, who move upward in wisdom and downward in compassion at the same time. The path to that unity is a difficult balancing act. ‘If one begins a career through wisdom, one will have to develop compassion, and vice versa the one who begins through compassion will have to purify it by wisdom’ (p. 17). Ludovic Viévard’s book, Vacuité (sûnyatâ) et compassion (karunâ) dans le bouddhisme madhyamaka (Collège de France, 2002),
Ludovic Viévard’s book, Vacuité (sûnyatâ) et compassion (karunâ) dans le bouddhisme madhyamaka (Collège de France, 2002),
Compassion extends first to beings, then to all dharmas, then it becomes objectless. The Buddha’s’ objectless compassion radiates spontaneously. It has become their very being. ‘Compassion is truly gratuitous and evident only for the Buddha’s and the great bodhisattvas, when it no longer has an object. The others are still tainted with views of me and mine, and thus prisoners of an egocentric vision… The great bodhisattvas and the Buddha’s practice a natural, “radiant” compassion without object (anâlambana-karunâ), which, says É. Lamotte, “acts mechanically”’ (p. 175).
Here the ultimate reality of compassion is defined as without object. Therefore compassion starts on the mundane level and becomes something different as we progress. But is in fact your wife not asking how can wisdom, i.e. Emptiness and Compassion be seen as compatible. Do they not logically oppose one another?
“For all who have not attained the objectless compassion of a Buddha, compassion, in practice, involves a descent from the heights of wisdom and a compromise with the dodgy realm of conventionality. Compassion accepts a certain residual bondage to the fleshly samsaric world in order to work toward a greater enlightenment, surpassing mere individual liberation. Bodhisattvas advance not by eventually abandoning compassion, as an entanglement with merely conventional beings, but by deepening it and applying to it the wisdom of emptiness at every step. “
“In essence the Madhyamaka see this conflict as merely illusory and say it has reality only for the ignorant and in convention and suggest Long meditation on the non-duality of wisdom and compassion as a practical project can perhaps prepare us to make better sense of the of an ultimate non-duality.”