Exodus 7:19-20

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.” 7:20 Moses and Aaron did so, just as the Lord had commanded. Moses raised the staff and struck the water that was in the Nile right before the eyes of Pharaoh and his servants, and all the water that was in the Nile was turned to blood.

Exodus 21:19

21:19 and then if he gets up and walks about outside on his staff, then the one who struck him is innocent, except he must pay for the injured person’s loss of time and see to it that he is fully healed.