Exodus 8:20

20.And the Lord said unto Moses, Rise up early. As Pharaoh advances in daring rashness, so does God on the other hand proceed to restrain his impetuosity by opposing impediments. This is what the wicked at length obtain by long and multiplied contention, that having received many wounds they perish by various torments. With respect to the command that Moses should meet Pharaoh, when he shall go down in the morning to the river-side for his pleasure, it is uncertain whether God would have the tyrant encountered in public, because the palace was difficult of access; although it seems probable to me, that a place was chosen in which the proceeding would be more manifest, and where the voice of His messenger would be more clearly heard. Therefore, that nothing might be done secretly, Moses proclaims in open day, before the whole multitude, that judgment of God, which immediately afterwards took effect. But here no mention is made of the rod, as in the former plagues; because God sometimes makes use of external instruments, that we may know that all creatures are in His hand, and are wielded according to His will; but sometimes acts independently of them, that we may know that He needs no such assistance. This varied mode of action demonstrates that He subjects all things to His empire as He pleases, and yet that He is contented with His own power. This plague has some affinity to the two previous ones, inasmuch as its infliction is attended with ignominy, which may put the tyrant to shame. The Hebrew word ערב, (95) g narob, means the same as the Latin “ examen insectorum, ” a swarm of insects. Many interpreters think that there was a mixture of various kinds; and this I do not reject, since it is probable that their foul odour was multiplied, so as almost to suffocate the tyrant. Those who explain it as describing bears, lions, tigers, wolves, and other wild beasts, depart without any reason from the genuine meaning of the word.