“And the magicians did so with their enchantments to bring forth lice, but they could not: so there were lice upon man, and upon beast. 19 Then the magicians said unto Pharaoh, This is the finger of God: and Pharaoh’s heart was hardened, and he hearkened not unto them; as the LORD had said (Ex. 8:18-19).”
The plague of lice was the third plague that the LORD unleashed on Egypt. The first two plagues were the waters of the Nile being turned to blood, and frogs covering the land (Ex. 7:19-22, 8:5-7). In both of these instances, the magicians of Egypt were able to imitate the plagues that God had done. The references mentioned make note that the magicians did so with their enchantments. While the magicians were allowed to be successful in replicating elements of the first two plagues, they failed doing the same for the third.
Upon failure, they rightly said, “This is the finger of God.” The LORD had just shown that his power was greater than the magicians. They surely knew that more plagues would be coming if the Pharaoh did not let the Hebrews go worship the LORD in the wilderness. The Pharaoh did not allow the Hebrews to do so, and so the plagues continued. During the plague of boils, the magicians were so powerless that they could not even stand before Moses (Ex. 9:11).
It is worth noting that the magicians were once viewed as powerful. They were then shown to be limited in that power. They confessed that God had done something that they could not do as well. They were rightly humbled, just as we all should be humble before God.