Moses and Aaron did as the LORD commanded repeats similar phrases in verses 6 and 10. In the same narrative style, following a detailed account of what the LORD commanded them to do, it introduces the action. Another way to express this is “Moses and Aaron obeyed the LORD.” Verses 14-18 explain what commands were given to Moses, and verse 19 gives the LORD’s command to Aaron through Moses. In the sight of Pharaoh is literally “to the eyes of Pharaoh,” meaning “in the presence of the king” (Good News Translation). But it may also be stated more dynamically, as in New American Bible, “in full view of Pharaoh.” In the sight of his servants means the same thing, so the two phrases may be combined, as in Translator’s Old Testament, “while Pharaoh and his officials were watching,” or even “as the king and his officials watched” (Contemporary English Version).

He lifted up the rod is ambiguous. The pronoun he is singular and may refer to either Moses or Aaron. There is no suggestion that both men used their rods. The translator must choose either to be literal or to be dynamic, either to preserve the ambiguity or to place the rod in either Moses’ or Aaron’s hand. Most translations have chosen to be literal, but a few have tried to identify who he was. On the basis of verse 19, Good News Translation has “Aaron raised his stick” (similarly New American Bible, Die Bibel im heutigen Deutsch, Biblia Dios Habla Hoy, and Bible en français courant). But on the basis of verse 17, Translator’s Old Testament has “Moses raised his staff.” Aaron is probably the better choice, but a footnote should explain that the Hebrew simply has he.

And struck the water means, of course, that he struck “the surface of the river” (Good News Translation) with the rod, bringing it down swiftly after having raised it for everyone to see (so also verse 17). All the water that was in the Nile means the entire Nile River. This may be an exaggerated statement, or hyperbole, intended as a literary device, but the translator should not try to revise this claim on the basis of verse 22. Turned to blood means that the water was substantially “changed into blood” (New International Version, New English Bible).

Quoted with permission from Osborn, Noel D. and Hatton, Howard A. A Handbook on Exodus. (UBS Helps for Translators). New York: UBS, 1999. For this and other handbooks for translators see here .