Midrasch zu Bamidbar 9:11

“He brought the contents of His quiver into my kidneys” (Lamentations 3:13).
“He brought the contents of His quiver [benei ashpato] into my kidneys” – Rav and Shmuel: Rav said: His prisoners and hostages;²¹The word benei generally is used in reference to people. Rav expounds that prisoners and hostages were appointed as guards over the Jewish prisoners. These individuals were bitter and cruel (Midrash HaMevo’ar). Shmuel said: He brought upon me people who eat much and excrete excrement [ashpot].²²The reference is to the Persians (see Megilla 11a).
“I have become a laughingstock to all my people, their song all day” (Lamentations 3:14).
“I have become a laughingstock to all my people” – it is written: “Those who sit at the gate talk about me” (Psalms 69:13) – these are the nations of the world who sit in theaters and circuses. “I am the subject of songs by ale drinkers” (Psalms 69:13) – after they sit, eat, drink, and become intoxicated, they sit, speak about me, mock me, and say: So that we will not need to eat carobs like the Jews.²³We have eaten as much as we like, unlike the Jews who are poor and must carobs [ḥarovim]. Alternatively, this sentence can be translated to mean: We will not be destroyed [ḥaruvim] like the Jews (Matnot Kehuna). They would say to each other: ‘How many years do you want to live?’ They would say: ‘Like the Shabbat garment of the Jews.’²⁴The Jews would wear their Shabbat clothes for many years. The gentiles mocked them for this as well. They would bring the camel into their theaters with its garments²⁵Sackcloth was used as a covering for camels and as clothes for mourners (Etz Yosef). on it. They would say to each other: ‘Why is it mourning?’ They would say: ‘These Jews observe the Sabbatical Year. They do not have any vegetation and they eat its thorns, and it is mourning over them.’ They would bring the dead into their theater and its head was shaved. They would say to each other: ‘Why is this one’s head shaved?’ He would say: ‘These Jews are Shabbat observers, and everything for which they exert themselves all the days of the week, they eat on Shabbat. They do not have wood with which to cook, and they break their beds and cook with them. They sleep on the ground and become covered with dirt, and they smear themselves with oil. Therefore, the oil is expensive.²⁶They cannot afford oil to shampoo their hair, so they shave it.
Another matter: “Those who sit at the gate talk about me” – these are Israel, who sit in the synagogues and study halls. “I am the subject of songs by ale drinkers” – after they sit, eat, drink, and become intoxicated at the meal prior to the ninth of Av, they sit and recite lamentations, wailing, with eikha.
“He filled me with bitterness, sated me with wormwood” (Lamentations 3:15).
“He filled me with bitterness” – this is the first festival day of Passover, in whose regard it is written: “With unleavened bread and bitter herbs [they shall eat it]” (Numbers 9:11). “Sated me with wormwood” – with what He filled me on the evening of the first festival day of Passover, He sated me on the ninth of Av. That is why the evening of the first festival day of Passover coincides with the evening of the ninth of Av.²⁷They occur on the same day of the week each year.