know, dawn

曉 is composed of the 日 (sun) and 堯 (embankment). 堯 is a protruding mound, which means high place. The sun illuminates the world, making things appear clearly, and standing at a high place makes it easier to see the whole of things, so 曉 has the meaning of knowing. In addition, when the sun has just risen, you have to stand at a high place to see it, so the 曉 is used to express the earliest period of day.