The actions of bodhisattvas refers to the six perfections, i.e., the six paramitas of generosity, etc.. Paramita is the Sanskrit word generally translated as perfection, but literally it means having gone to the other side. The other side is enlighenment, which is a state free from obscuration, and to reach it one needs the realization of emptiness. Perfecting generosity for example, does not just mean to increase the generosity per se, but to also purify it with emptiness, i.e., with the wisdom realising the emptiness of the 3 circles. The emptinesses of the 3 circles are the emptiness of the giver, of the object and of the recipient.