Exodus 7:9
7:9 “When Pharaoh says to you, ‘Do a miracle,’ and you say to Aaron, ‘Take your staff and throw it down before Pharaoh,’ it will become a snake.”
Exodus 7:19
7:19 Then the Lord said to Moses, “Tell Aaron, ‘Take your staff and stretch out your hand over Egypt’s waters – over their rivers, over their canals, over their ponds, and over all their reservoirs – so that it becomes blood.’ There will be blood everywhere in the land of Egypt, even in wooden and stone containers.”