Exodus 8:2

2. I will smite all thy borders with frogs--Those animals, though the natural spawn of the river, and therefore objects familiar to the people, were on this occasion miraculously multiplied to an amazing extent, and it is probable that the ova of the frogs, which had been previously deposited in the mire and marshes, were miraculously brought to perfection at once.

Robert Jamieson, A. R. Fausset & David Brown, 1871 · public domain

Verse 2 If thou refuse - Nothing can be plainer than that Pharaoh had it still in his power to have dismissed the people, and that his refusal was the mere effect of his own wilful obstinacy. With frogs - צפרדעים tsepardeim. This word is of doubtful etymology: almost all interpreters, both ancient and modern, agree to render it as we do, though some mentioned by Aben Ezra think the crocodile is meant; but these can never weigh against the conjoint testimony of the ancient versions. Parkhurst derives the word from צפר tsaphar, denoting the brisk action, or motion of the light, and ידע yada, to feel, as they seem to feel or rejoice in the light, croaking all the summer months, yet hiding themselves in the winter. The Arabic name for this animal is very nearly the same with the Hebrew zafda, where the letters are the same, the ר resch being omitted. It is used as a quadriliteral root in the Arabic language, to signify froggy, or containing frogs: see Golius. But the true etymology seems to be given by Bochart, who says the word is compounded of zifa, a bank, and rada, mud, because the frog delights in muddy or marshy places; and that from these two words the noun zafda is formed, the re being dropped. In the Batrocho myomachia of Homer, the frog has many of its epithets from this very circumstance. Hence Λιμνοχαρις, delighting in the lake; Βορβοροκοιτης, lying or engendering in the mud; Πηλευς, and Πηλβατης, belonging to the mud, walking in the mud, etc., etc. A frog is in itself a very harmless animal; but to most people who use it not as an article of food, exceedingly loathsome. God, with equal ease, could have brought crocodiles, bears, lions, or tigers to have punished these people and their impious king, instead of frogs, lice, flies, etc. But had he used any of those formidable animals, the effect would have appeared so commensurate to the cause, that the hand of God might have been forgotten in the punishment; and the people would have been exasperated without being humbled. In the present instance he shows the greatness of his power by making an animal, devoid of every evil quality, the means of a terrible affliction to his enemies. How easy is it, both to the justice and mercy of God, to destroy or save by means of the most despicable and insignificant of instruments! Though he is the Lord of hosts he has no need of powerful armies, the ministry of angels, or the thunderbolts of justice, to punish a sinner or a sinful nation; the frog or the fly in his hands is a sufficient instrument of vengeance.

Adam Clarke, 1831 · public domain