וַיַּֽעֲשׂוּ־כֵ֥ן הַֽחֲרְטֻמִּ֖ים בְּלָטֵיהֶ֑ם וַיַּעֲל֥וּ אֶת־הַֽצְפַרְדְּעִ֖ים עַל־אֶ֥רֶץ מִצְרָֽיִם׃
개구리가 하수에서 무수히 생기고 올라와서 네 궁에와 네 침실에와 네 침상 위에와 네 신하의 집에와 네 백성에게와 네 화덕에와 네 떡반죽 그릇에 들어갈지며
Sforno
ויעלו את הצפרדעים, the ones produced by the sorcerers were unable to reproduce themselves, as were those that Aaron had produced. The sorcerers were never able to produce any creature that could move on its own. [It is important to realise that our author considers the צפרדע as a type of crocodile, the major danger to humans and fish inhabiting the Nile. Ed.]
Chizkuni
בלטיהם, “with their spells.” According to Rashi, these “spells” are called such as the word means “silently,” they employed whispers to produce such illusions. Rashi had given this interpretation already on 7,11 where the spelling of the word had been slightly different.
Tur HaArokh
ויעשו כן החרטומים, “the sorcerers did likewise. “They succeeded in making frogs emerge from the relatively few ponds which had not yet produced frogs. Seeing that they were unable to make the frogs retreat to their natural habitat, [presumably this had been the task set for them by Pharaoh Ed.] Pharaoh saw himself compelled to appeal to Moses and Aaron to pray to their G’d to stop the plague.