Today is the song of the ox. The ox sings the famous, first song of Jewish history, Az Yashir
אָז יָשִׁיר משֶׁה וּבְנֵי יִשְׂרָאֵל אֶת הַשִּׁירָה הַזֹּאת לַיי וַיֹּאמְרוּ לֵאמֹר אָשִׁירָה לַּיְיָ כִּי גָאֹה גָּאָה סוּס וְרֹכְבוֹ רָמָה בַיָּם: (שמות טו א)
Then Moshe and the Jewish people will sing the song to Hashem, saying, Sing to Hashem for He is arrogant, above all those that are arrogant. (meaning He's more powerful than those that think they're powerful)..
What does this have to do with the shor/ox?
The Chida says the shor hints to Yosef. In the blessing that Moshe Rabbenu gives him in Zot Haberacha, 33,17 בְּכ֨וֹר שׁוֹר֜וֹ הָדָ֣ר ל֗וֹ וְקַרְנֵ֤י רְאֵם֙ קַרְנָ֔יו, Yosef is compared to the shor, and furthermore, in the merit of Yosef , the sea split as it says Hayam Ra'ah V'Yanos/the sea saw something and split- it saw the casket of Yosef.
Because Yosef ran away from his boss's wife, the sea ran away from the Jewish people. And because Yosef, the power of the ox, caused the sea to split, that is the song of the ox.
The sefer Pi Eliyahu adds, based on the Gemara in Masechet Hagiga 13B, that there are four arrogant ones in the world. The lion among the wild animals, the ox among the domesticated animals, the eagle among the birds, and Adam who's more arrogant than all of them. Each of their faces on are on the Kiseh Hakavod, as if to say that Hashem sits on His holy throne and they're under Him. He is above them. So the ox says, Although I'm the most arrogant of animals, I will sing this song because I understand and recognize that Hashem is above me. Possibly, because the ox is a kosher animal, it has the merit to sing that song, whereas the other creatures do not.
The sefer Yesod Yosef, in chapter 83, adds that the Gemara in Berachot 33A says that if you see a black ox in the month of Nisan, in the springtime, or what's called spring fever, stay far away because the Satan is dancing between his horns. He explains that the horns are where his power and strength are. Dancing between the horns means his arrogance is in his horns because that's where his strength is. Furthermore, about Yosef it says, his strength is also in his horns. So, this powerful ox, with his strength in his horns, is saying,
With all my strength and all my power, the bull fights and the like, the One who ultimately rules everything is Hashem, as He showed at the splitting of the sea.
For a bit of a deeper explanation, we know that the Jewish people sinned the sin of the golden calf. The reason they made the mistake of the sin of the golden calf, the Ramban says, is because they looked at God's throne. This was not Avoda Zara.They knew there was a God. But they felt that they they needed an intermediary. They thought Moshe wasn't there to lead them. So they chose the ox because the ox gores, and is powerful, and thought that force of God would lead them through the desert. Since they focused on the ox as their leader, the ox, so to say, wanted to excuse itself, says Rabbi Binyamin HaKohen. The ox wanted to excuse himself that the Jewish people stumbled because of him. He wanted to let the world know, It wasn't my fault. Even though I am the king of the domesticated animals, I know who the real Boss is-don't think that I had anything to do with this mistake..
That is why the ox wants to sing this song.
To tie everything together, Rav Yonatan Eyebeschutz says in his sefer Targum Yonatan, based on Bereshit 37,18 where it says וַיִּרְא֥וּ אֹת֖וֹ מֵרָחֹ֑ק/ and they saw him from afar that the reason the brothers sold Yosef was because they felt he was a threat to the Jewish people. Not just because of what he told his father, but because וַיִּרְא֥וּ אֹת֖וֹ מֵרָחֹ֑ק/ and they saw him from afar, they saw the future and saw that Yerovam ben Nevat (we can't judge him) who was a sinner, would come from Yosef. The Mesilat Yesharim adds that Yeravam ben Nevat ultimately fell because of arrogance. God told Yeravam, Return and you and David will walk with Me and Yaravam asked, Who will be first? When Hashem said that David would be first, Yeravam said, No thank you. So it was his arrogance that brought him down. And what was Yeravam's sin? It says he created a temple with the two golden calves, because he came from Yosef, and the power of Yosef is the calf.
He said that the mistake of the golden calf was that they were in the desert and thus should have used a lion. Calves are domesticated. They don't belong in deserts, they belong in Israel. He had a whole theory as to why the calves were corrupt. So when the brothers saw in the future, that from Yosef would come Yeravam ben Nevat, who was a great threat for the Jewish people, they wanted to end it at the source, which was Yosef. As we know, Yaakov and Yosef had similar looking faces. The Adam, the man on the God's throne, is Yaakov. The ox, which was later switched to a child, is the face of Yosef (after the sin of the golden calf, they prayed that the ox should be replaced with a child). But who is this child? The child is Yosef. It's his face on the Kiseh HaKavod, because he's the child of Yaakov..
That being said, the ox was held responsible, and Yosef was held responsible, so to say, for all of this downfall. And therefore ,Yosef says No, I'm not arrogant. I realize the arrogance belongs to Hashem. Yeravam was arrogant, but it was not my fault. I don't want to be connected to that, just like Yaakov didn't want to be connected to Korach. So Yosef did not have responsibility, and therefore the ox and Yosef sing that Hashem is the One that is the ultimate King.
