They had no way of measuring its depth or extension, so it seemed boundless, and what it contained also seemed unlimited. The idea of the ocean as boundless and able to contain unlimited things was used as a metaphor for the vow of the bodhisattva. It contains limitless waves of compassion. The buddhas' and bodhisattvas' minds move with waves of compassion for sentient beings. Because of their compassion, they are willing to work hard to help sentient beings.
Wisdom is the driving force of a bod-hisattva's actions.
With the guidance of wisdom, actions will not be deflected onto erroneous paths. Wisdom is complete awakening. When you are completely awakened, you will no longer do evil, and you can truly help sentient beings. Compassion is the ability to communicate with all sentient beings and to help them to accomplish the Buddhadharma. To make the Bodhisattva vow is not enough.