Exodus 8:18 New English Translation

¹⁸When^[a] the magicians attempted^[b] to bring forth gnats by their secret arts, they could not. So there were gnats on people and on animals.

Exodus 8:18 tn The preterite with vav (ו) consecutive is here subordinated to the main clause as a temporal clause.
Exodus 8:18 tn Heb “and the magicians did so.”sn The report of what the magicians did (or as it turns out, tried to do) begins with the same words as the report about the actions of Moses and Aaron—“and they did so” (vv. 17 and 18). The magicians copy the actions of Moses and Aaron, leading readers to think momentarily that the magicians are again successful, but at the end of the verse comes the news that “they could not.” Compared with the first two plagues, this third plague has an important new feature, the failure of the magicians and their recognition of the source of the plague.

New English Translation (NET)