Midrasz do Zachariasza 9:9

And I have oxen. This implies that I have no need to fear you (he was thinking to himself), for now Joseph is born, who is called an ox, as is said: His firstling ox, majesty is his (Deut. 33:17). Asses. The word ass alludes to the Messiah the son of David, as it is said: Lowly and riding upon an ass (Zech. 9:9). Flocks refers to the merit of the tribes, whose descendants will be called flock, as is said: And ye My sheep, the flock of My pasture (Ezek. 34:31).

It is because of the reward given to those who devote themselves to the Torah that Isaiah declared: Happy are ye that sow beside all waters, that send forth freely the feet of the ox and the ass (ibid. 32:20). The words that sow beside all waters refer to those who devote themselves to the study of the Torah, which is compared to water, as it is said: Ho! Everyone that thirsteth, come ye for water (ibid. 55:1); the word ox alludes to the Messiah of the House of Joseph,⁷A descendant of the house of Joseph will precede the coming of the Davidic Messiah. Cf. B. Sukkah 52a. who is compared to an ox; and the ass refers to the Messiah of the House of David, for it is said of him: Lowly and riding upon an ass (Zech. 9:9).

“Let us exult and rejoice in you.” Ten expressions of joy are employed in Israel’s regard: Gila, sisa, simḥa, rina, pitzḥa, tzahala, alatza, elza, ḥedva, terua. Gila, “rejoice [gili] greatly, daughter of Zion” (Zechariah 9:9); sisa, “I will be gladdened [sos asis] in the Lord” (Isaiah 61:10); simḥa, “rejoice [simḥu] with Jerusalem” (Isaiah 66:10); rina, “sing [roni] and rejoice, daughter of Zion” (Zechariah 2:14); pitzḥa, “burst [pitzḥi] into song and rejoice” (Isaiah 54:1); tzahala, “shout [tzahali] and sing” (Isaiah 12:6); alatza, “my heart rejoices [alatz] in the Lord” (I Samuel 2:1); elza, “my heart exults [vaya’aloz], and with my song I give thanks to Him” (Psalms 28:7); ḥedva, “the children of Israel…performed [the dedication of this House of God with joy [beḥedva]]” (Ezra 6:16); terua, “shout with joy [hariu] to the Lord, all the earth” (Psalms 98:4), “shout [hariu] to God with a joyous voice” (Psalms 47:2). There are some who remove terua and insert ditza, just as you say: “Anguish rejoices [tadutz] before it” (Job 41:14); it dances like that mudfish.