Discovery BoxExodus 7:19-20 
Context7:19 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, 1 over their ponds, and over all their reservoirs 2 – so that it becomes 3 blood.’ There will be blood everywhere in 4 the land of Egypt, even in wooden and stone containers.” 7:20 Moses and Aaron did so, 5 just as the Lord had commanded. Moses raised 6 the staff 7 and struck the water that was in the Nile right before the eyes 8 of Pharaoh and his servants, 9 and all the water that was in the Nile was turned to blood. 10
1 tn Or “irrigation rivers” of the Nile.
2 sn The Hebrew term means “gathering,” i.e., wherever they gathered or collected waters, notably cisterns and reservoirs. This would naturally lead to the inclusion of both wooden and stone vessels – down to the smallest gatherings.
3 tn The imperfect tense with vav (ו) after the imperative indicates the purpose or result: “in order that they [the waters] be[come] blood.”
4 tn Or “in all.”
5 sn Both Moses and Aaron had tasks to perform. Moses, being the “god” to Pharaoh, dealt directly with him and the Nile. He would strike the Nile. But Aaron, “his prophet,” would stretch out the staff over the rest of the waters of Egypt.
6 tn Heb “And he raised”; the referent (Moses) has been specified in the translation for clarity.
7 tn Gesenius calls the preposition on “staff” the בְּ (bet) instrumenti, used to introduce the object (GKC 380-81 §119.q). This construction provides a greater emphasis than an accusative.
8 tn The text could be rendered “in the sight of,” or simply “before,” but the literal idea of “before the eyes of” may stress how obvious the event was and how personally they were witnesses of it.
9 sn U. Cassuto (Exodus, 98) notes that the striking of the water was not a magical act. It signified two things: (1) the beginning of the sign, which was in accordance with God’s will, as Moses had previously announced, and (2) to symbolize actual “striking,” wherewith the Lord strikes Egypt and its gods (see v. 25).
10 sn There have been various attempts to explain the details of this plague or blow. One possible suggestion is that the plague turned the Nile into “blood,” but that it gradually turned back to its normal color and substance. However, the effects of the “blood” polluted the water so that dead fish and other contamination left it undrinkable. This would explain how the magicians could also do it – they would not have tried if all water was already turned to blood. It also explains why Pharaoh did not ask for the water to be turned back. This view was put forward by B. Schor; it is summarized by B. Jacob (Exodus, 258), who prefers the view of Rashi that the blow affected only water in use.
