《淮南子·诠言训》
这前一种情况无处发怒，后一种情况发怒谩骂，这是因为前一种情况是空船，后一种情况是船上有人。
向不怒而今怒，向虚而今实也。
In the first case there was nowhere to vent anger, in the second case there was anger and scolding, this was because in the first case it was an empty boat, in the second case there was someone on the boat.