51. Moses was holding a rod, he cast it down and it became a serpent. Ex. iv. 3, 4. Again, he took hold of the tail of the serpent and it returned to the nature of a rod. You see that by virtue of the prophetic office there were two changes, of the nature both of the serpent and of the rod. The streams of Egypt were running with a pure flow of water; of a sudden from the veins of the sources blood began to burst forth, and none could drink of the river. Again, at the prophet’s prayer the blood ceased, and the nature of water returned. Ex. vii. 20 ff. The people of the Hebrews were shut in on every side, hemmed in on the one hand by the Egyptians, on the other by the sea; Moses lifted up his rod, the water divided and hardened like walls, and a way for the feet appeared between the waves. Ex. xiv. 21 ff. Jordan being turned back, returned, contrary to nature, to the source of its stream. Josh. iii. 16. Is it not clear that the nature of the waves of the sea and of the river stream was changed? The people of the fathers thirsted, Moses touched the rock, and water flowed out of the rock. Ex. xvii. 6. Did not grace work a result contrary to nature, so that the rock poured forth water, which by nature it did not contain? Marah was a most bitter stream, so that the thirsting people could not drink. Moses cast wood into the water, and the water lost its bitterness, which grace of a sudden tempered. Ex. xv. 25. In the time of Elisha the prophet one of the sons of the prophets lost the head from his axe, which sank. He who had lost the iron asked Elisha, who cast in a piece of wood and the iron swam. This, too, we clearly recognize as having happened contrary to nature, for iron is of heavier nature than water.