The second plague is of frogs: Pharao promiseth to let the Israelites go, but breaketh his promise. The third plague is of sciniphs. The fourth is of flies. Pharao again promiseth to dismiss the people, but doth it not.
And the river shall bring forth an abundance of frogs: which shall come up, and enter into thy house, and thy bedchamber, and upon thy bed, and in the houses of thy servants, and to thy people, and into thy ovens, and into the remains of thy meats;
And Moses said to Pharao: Set me a time when I shall pray for thee, and for thy servants, and for thy people, that the frogs may be driven away from thee and from thy house, and from thy servants, and from thy people: and may remain only in the river.
And he answered: Tomorrow. But he said: I will do according to thy word; that thou mayst know that there is none like to the Lord our God.
 "Pray ye to the Lord": By this it appears, that though the magicians, by the help of the devil, could bring frogs, yet they could not take them away: God being pleased to abridge in this the power of Satan. So we see they could not afterwards produce the lesser insects; and in this restraint of the power of the devil, were forced to acknowledge the finger of God.
And Pharao seeing that rest was given, hardened his own heart, and did not hear them, as the Lord had commanded.
 "Hardened his own heart": By this we see that Pharao was himself the efficient cause of his heart being hardened, and not God.-- See the same repeated in ver. 32. Pharao hardened his heart at this time also: likewise chap. 9. 7, 35, and chap. 13. 15.
And they did so. And Aaron stretched forth his hand, holding the rod: and he struck the dust of the earth, and there came sciniphs on men and on beasts: all the dust of the earth was turned into sciniphs through all the land of Egypt.
But if thou wilt not let them go, behold I will send in upon thee, and upon thy servants, and upon thy houses all kind of flies: and the houses of the Egyptians shall be filled with flies of divers kinds, and the whole land wherein they shall be.
And Moses said: It cannot be so: for we shall sacrifice the abominations of the Egyptians to the Lord our God: now if we kill those things which the Egyptians worship, in their presence, they will stone us.
And Moses said: I will go out from thee, and will pray to the Lord: and the flies shall depart from Pharao, and from his servants, and from his people tomorrow: but do not deceive any more, in not letting the people go to sacrifice to the Lord.
So Moses went out from Pharao, and prayed to the Lord.
 "The abominations": That is, the things they worship for Gods: oxen, rams, etc. It is the usual style of the scriptures to call all idols and false gods, abominations, to signify how much the people of God ought to detest and abhor them.