Exodus 7:19

And the LORD spake unto Moses, Say unto Aaron, Take thy rod, and stretch out thine hand upon the waters of Egypt, upon their streams, upon their rivers, and upon their ponds, and upon all their pools of water, that they may become blood; and {that} there may be blood throughout all the land of Egypt, both in {vessels of} wood, and in {vessels of} stone. {pools...: Heb. gathering of their waters}