Four Immeasurables, Loving Kindness Line

So here's the first line of the four immeasurables: May all sentient beings have happiness and the causes of happiness.

This is the limitless loving-kindness aspiration as well as activity, to make sure all sentient beings, whoever they are, known or unknown, friend or foe, that they all should be happy and have all the causes of happiness. The amount of sentient beings is limitless, so the karma created from this thinking and action is also limitless.