One theologian has written, "The traditional loci of general revelation are three: nature, history, and the constitution of the human being" (Millard Erickson, Christian Theology, 3rd. ed., p. 123). General revelation does not occur through human words, then, but we can see the image of God and His glory in creation, in how a human being is made, and throughout human history, such as when the North won the Civil War, or the Normandy Invasion took place in WW2.
It often occurs through nature, such as when a tribal native looks up at the sky and says, "There must be a God. Dear God, reveal yourself to me." One such event is recorded in a book by my great uncle, evangelist Bill Rice, Cowboy Boots in Darkest Africa. The man who prayed that was a pygmy, and his prayer was answered when my uncle, a missionary, and an interpreter arrived in his village years later.