Commentary for Exodus 8:14

להוציא את הכנים TO BRING FORTH GNATS — to create them and to bring them forth from some other place (not from dust but to turn some other material into gnats).

AND THE MAGICIANS DID SO WITH THEIR SECRET ARTS TO BRING FORTH GNATS. The purport of the expression, and the magicians did so, [when it immediately says afterwards, but they could not], is that they hit the dust of the earth and incanted the demons and performed their secret arts, as they used to do at other times, in order to bring forth the gnats, but they could not. It is possible that the expression, and the magicians did so, teaches that they did indeed do the correct things which do bring forth the gnats, but they were not successful this time, [for G-d thwarted their plans]. The learned magicians knew what they could do and they had tried to do so at other times [and succeeded. Hence they tried to do it now, but they failed “because it was now the will of the Holy One, blessed be He, to remove that power from them henceforth],”¹⁴¹From Ramban’s sermon on Torath Hashem T’mimah. See my Kithvei Haramban, I, p. 146.

ולא יכולו. They were unable to produce anything which could truly move on its own.