Midras Keluaran 8:3: Midrash Tehillim & Shemot Rabbah

Another thing about the death of Levan. Solomon said (Song of Songs 8:4): "I adjure you, O daughters of Jerusalem, that you not stir up or awaken love until it pleases." I am sick with love, a love that is not of the bowels or of the head. From what do I suffer? "For I am love-sick" (Hosea 2:7). And not just love, but also death, as it says (Song of Songs 8:6), "For love is strong as death." As it says (Song of Songs 1:3), "Your oils have a pleasing fragrance, your name is like purified oil; therefore the maidens love you." What nation in the world did God tell to "descend to the sea"? Only the Jews, as David said (Psalms 27:10), "When my father and my mother forsake me, then the Lord will take me up." Similarly, Nebuchadnezzar said (Daniel 3:15), "And who is the god that will deliver you out of my hands?" And it is written (Daniel 3:16), "We will not serve thy gods, nor worship the golden image which thou hast set up." But to deny God, Nebuchadnezzar and the dog are the same. They even have the same fate as the frogs, as it says (Exodus 8:3), "And the river shall swarm with frogs, and they shall go up and come into your house and into your bedchamber and onto your bed and into the houses of your servants and your people, and into your ovens and into your kneading bowls." And even if God does not save us, we will not abandon Him. What did Nebuchadnezzar say when they came out of the furnace? "Nebuchadnezzar answered and said, 'Blessed be the God of Shadrach, Meshach, and Abednego, who has sent His angel and delivered His servants who trusted in Him and set aside the king's command and yielded up their bodies rather than serve and worship any god except their own God'" (Daniel 3:28). They did not give themselves up in order to be saved, but in order to be burned. Why "For love is strong as death" (Song of Songs 8:6)? A song to be sung over the death of Levan.

“The Lord said to Moses: Say to Aaron: Extend your hand with your staff over the rivers, over the canals, and over the pools, and cause frogs to ascend upon the land of Egypt” (Exodus 8:1).
“The Lord said to Moses: Say to Aaron: Extend your hand” – Rabbi Tanḥum said: The Holy One blessed be He said to Moses: ‘The water that protected you when you were cast into the Nile will not be stricken by you.’
“Aaron extended his hand over the waters of Egypt; and the frogs ascended and covered the land of Egypt” (Exodus 8:2).
“Aaron extended his hand” – why did He bring frogs upon them? It is because they were enslaving Israel and saying to them: ‘Bring us repugnant creatures and creeping animals’;¹¹The Israelites considered this a revolting and humiliating task. therefore, He brought frogs upon them. When they would pour into a cup it would fill with frogs. “And the frogs [hatzfarde’a]¹²Both Rabbi Akiva and Rabbi Elazar ben Azarya expound their opinions from the fact that the Hebrew word for frogs is in the singular. ascended and covered…” – it is taught: Rabbi Akiva says: It was one frog, and it spawned and filled the entire land of Egypt. Rabbi Elazar ben Azarya said to him: ‘Akiva, what are you doing engaged in aggada; stop your statements, and go engage in the laws of leprosy and impurity of tents.¹³Your expertise is in matters of halakha, including the most intricate topics, but not aggada. There was one frog that whistled to [the others], and they came.’
“The magicians did so with their spells, and caused the frogs to ascend upon the land of Egypt” (Exodus 8:3).
“The magicians did so with their spells” – because they believed these were the actions of demons.