פּירוש אויף שמות 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).

להוציא את הכננים, “to remove the lice and vermin;” seeing that the lice had lodged between the feet of the sorcerers and the ground, an area over which sorcery has no control. We have learned about this from something that happened at the time of Shimon ben Shetach (early part of the second Temple period) and the young men lifted these female sorcerers from the ground (Before executing them. Compare Jerusalem Talmud, tractate Chagigah second chapter, halachah 2) The three first plagues were, blood, frogs, and lice, were initiated by Aaron as they affected the earth. The three plagues of hail, locust, and darkness were initiated by Moses, as they originated in the celestial spheres, something over which Moses exercised a degree of control. The three plagues, of roaming beasts invading urban areas, the boils and the plague, were initiated by both G–d, Moses and Aaron jointly. (Tanchuma on this portion, section 14)

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 יכלו BUT THEY COULD NOT — for the demon (through whose agency this was to be done) is powerless in the case of a creature smaller than a barley corn) (Sanhedrin 67b). Therefore they had to admit,