When we release the contracted sense of self, we will automatically have compassion flowing. It will be there without effort, that is the beauty and that is what we can trust. But we must first give it to ourselves. If we are doing this, the contracted sense of self can relax and expand. Giving love and compassion to oneself is a first and foremost requirement on our path.
Compassion is one of the core values and ideals of the Buddhist practice. However, as seeing it as an ideal, it becomes easy to overlook the difficult circumstances in which it arises. Compassion does not appear as something abstract. It arises when we are in a direct contact with real suffering, being enough to move and touch us, through our own suffering or the suffering of others.
Unless and until our experience of nondual awakened mind is for real, there is every reason in the world to pursue teachings on, to understand and train in the most eminent kind of dualistic mind.