Nothing is ever wasted.
All karma is simply action. From the tiniest of amoeba, to the most grand human being or great Bodhisattva, we’re perfecting basic mundane virtues. These virtues eventually evolve into the “perfections” (the paramitas) of Bodhisattva practice. They are the core elements that form our functional world view in the Great Vehicle.
We may start with something as simple as effort (to survive) and round out a life with the (very mundane, but still generous) practice of giving (dana), by caring for a mate, cubs, baby chicks, human children, and graduate to caring for our extended clan, for our nation, or even for the entire Earth and beyond this tiny planet. All beings are practicing whether or not they are doing so consciously. Thus does Mahayana sometimes explain the Buddha Nature of all beings. Even if unconsciously, all beings (and moreover, all dharmas, or “existents”) play a role in our practice because that’s the kind of cosmos we inhabit.
Intention is also a kind of action–a very special kind of action. It is an action of the will. When we intend something, we plant a seed of intention that will grow to affect our becoming into a certain kind of being going forward from that moment. When we as Bodhisattvas vow to save all beings, we plant a special kind of intention-seed. This seed is a seed of our desire to fulfill what is the purpose of every being in this cosmos of ours. So when we intend that, we are making a major leap forward. We now choose our grand destiny. And by choosing, presumably, we can come closer, faster, and more steadfastly into our true mission on the Earth.
Why such a major leap? Because when we consciously intend to fulfill our long-range mission, this means we loosen numberless obstructions along our path from that spot in that current lifetime, in this current set of circumstances. This is like blowing up the bridges of delusion that lead the trains of our desires into a million alternate detours of becoming. We vow to live for the welfare of all beings. That’s like breathing in your past, present and future lives and saying “full steam ahead!”. Now you are like an arrow sailing straight through the air toward its mark.
Being with the vow to save all beings is one of the most precious things (really, it’s the most precious) that we will encounter as human begins. The vow not only makes the Eightfold Path visible, but brings it within reach.
The vow may start out small: “I vow it, yeah yeah…” and later grow into something more intentional and profound “I…vow…to save…all beings!” and on until it has become like an unspoken mantra in the background of every movement, every spoken word, every gesture.
This unspoken mantra is the practice itself. It is, therefore, the unspoken mantra which is the context of “just sitting” in Soto Zen tradition of zazen (shikantaza in Japanese). We sit amidst an awareness of all the suffering of all beings, everywhere. We sit down to work toward the realizing of the supreme enlightenment for their sakes.