We know that “seeing” can have two meanings: one is to physically see, and the other is to understand. This is how Rashi explains the double wording of וירא in the episode of Avraham and the malachim where it says וישא עיניו וירא... וירא וירץ לקראתם, he lifted his eyes and saw and behold, three men were standing before him. He saw and he ran toward them from the entrance of the tent. The first וירא refers to physically seeing with his eyes while the second וירא refers to understanding. Avraham observed that they were standing in one spot and he understood that they did not want to bother him.
We have a similar usage in English. “I see” can mean to literally see something with your eyes but it can also mean to understand, as in, “I see what you are saying.”
But why does “seeing” also imply understanding? The connection lies in the fact that when we physically see something, we can recognize, identify, and make sense of it. The same process happens when we grasp or understand something mentally.
