And the LORD did as Moses asked is a “preview” statement that summarizes what follows. (See the brief discussion on “preview” and “superscription” at 3.2a.) As Moses asked is literally “as Moses said,” so New Revised Standard Version adds a colon to show what it was that Moses had said in his prayer: “And the LORD did as Moses asked: he removed….” It is also possible to say “and the LORD answered his people” (similarly New Jewish Publication Society’s Tanakh and New International Version). It should be remembered, however, that punctuation marks are not read aloud. Therefore it may be possible to show this in other ways. The following clause should not suggest that Yahweh did something else in addition to what Moses asked.

And removed the swarms of flies may also be read as “The flies left” (Good News Translation, New International Version; similarly Jerusalem Bible, New Jerusalem Bible). However, since this clause explains what the first clause summarizes, it may be better to retain the LORD as the subject of the verb removed in its causative form, which is literally “he caused to go away the swarms of flies” (so New English Bible, New American Bible, New Jewish Publication Society’s Tanakh, and others). This avoids the possible misunderstanding that “the flies left” of their own free will. So one may translate the first part of this verse as “and the LORD answered his prayer, and caused the flies to leave the king….”

From Pharaoh, … people only repeats the same words used in verse 29. Not one remained should be understood as “not one fly remained” (Good News Translation), rather than “not one swarm remained.” The removal of the plague was complete.

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 .