Midrash su Geremia 49:24

Rabbi Papis expounded: “They exchanged their glory for the cast image of a [grass-eating] bull” (Psalms 106:20). I might understand that it was the heavenly bull;²³⁹This is one of the four beasts that draw the Divine Chariot. the verse [therefore] states: “Grass-eating.” Rabbi Akiva said to him: ‘Enough, Papis.’²⁴⁰Were that the meaning, it would have been sufficient to write “an eating bull.” He said to [Rabbi Akiva]: ‘And how do you interpret [the phrase]: “they exchanged their glory for the cast image of a [grass-eating] bull”?’ [Rabbi Akiva answered: ‘Perhaps it is a bull typical] of the rest of the days of the year?²⁴¹Perhaps it was an image of a bull when it is clean and nice looking. The verse states “grass-eating,” you do not have anything as repugnant and repulsive as a bull when it is eating grass.’²⁴²This is because the bull drools a lot while eating. Rabbi Yudan says in the name of Rabbi Aḥa: The Egyptian magicians performed sorcery for them and it appeared to be undulating [meratet] before them, just as you say: “Damascus has weakened. It turned to flee but was seized with trembling [retet]” (Jeremiah 49:24).