Midrash for Daniel 4:31

We know that Nebuchadnezzar claimed divinity, because it is written: I will ascend above the heights of the clouds; I will be like the Most High (Isa. 14:14). Thereupon the Holy One, blessed be He, said to him: Wretch! Yet thou shalt be brought down to the netherworld, to the uttermost parts of the pit (ibid., v. 15). What did He do to him? He exiled him into the desert though he was a king, and compelled him to eat grass like a beast, as it is said: Thou shalt be made to eat grass as oxen, and seven times shall pass over thee (Dan. 4:29). To the beasts and the cattle he appeared like a female beast, and they had intercourse with him, as it is said: The destruction of the beast, which made them afraid (yehitan) (Hab. 2:17). This corresponds to what is stated in the verse Neither shalt thou make marriages (tithaten) with them (Deut. 7:3). Nevertheless, a human heart was given to him so that he might realize that he had once ruled the entire world, and now was having intercourse with beasts and animals. And it is written about him: And at the end of the days, I Nebuchadnezzar lifted up my eyes unto heaven, and my understanding returned unto me, and I blessed the Most High, and I praised and honored Him that liveth forever (Dan. 4:31).