Midrasch zu Wajikra 26:18

1) (Vayikra 26:18) ("And if with these you do not hearken to Me, then I shall chastise you even more, seven-fold for your sins.") "with these" ("ad eileh"). R. Eliezer says: The Holy One does not bring calamity to Israel until he testifies ("me'id" [similar to" ad]) against them first, as it is written "And if ad eileh." R. Yehoshua says: Let Israel not say "The plagues have ended and He has no other to bring upon us"; it is, therefore, written "And if ad eileh" — still ("od [similar to "ad"]) I have others of these and like these to bring. Then I shall chastise you even more, seven-fold for your sins.": You transgressed seven transgressions ("not learning, not doing, etc.," viz. Section 2:3 above) — come and take upon yourselves seven calamities, (which follow).

“The Lord accomplished what He devised: He implemented His statement that He commanded from the days of old; He destroyed and had no compassion. He caused the enemy to rejoice over you, raised the horn of your antagonists” (Lamentations 2:17).
“Their heart cried to the Lord: Wall of the daughter of Zion, let tears fall like a stream, day and night; do not give yourself respite, let the apple of your eye not cease” (Lamentations 2:18).
“The Lord accomplished what He devised.” Rabbi Ahava son of Rabbi Ze’eira said: From the moment that the Holy One blessed be He said: “If despite this you do not heed Me…I, too, will walk with you casually” (Leviticus 26:18, 24), did He, Heaven forbid, do so? Rather, “the Lord accomplished [what He devised: He implemented [bitza] His statement that He commanded from the days of old].” He compromised.¹²¹The term bitzua also means compromise. Rabbi Yaakov of Kefar Ḥanan said: He rent [beza] His raiment.
“He caused the enemy to rejoice over you.” Rabbi Aḥa said: In good times, He rejoiced with them, as it is written: “For the Lord will return to rejoice over you for good, as He rejoiced over your fathers” (Deuteronomy 30:9). But in bad times, He causes others to rejoice. That is what is written: “He caused the enemy to rejoice over you, raised the horn of your antagonists.” In that regard it is said: “Their heart cried to the Lord: Wall of the daughter of Zion, [let tears] fall…”¹²²God caused the enemies to rejoice but He did not rejoice with them.

Rabbi Pinḥas began: “If after these you will not heed Me…” (Leviticus 26:18). Rabbi Eliezer and Rabbi Yehoshua: Rabbi Eliezer says: The Holy One blessed be He does not bring punishment upon Israel until He first warns them. That is what is written: “If after these.” Rabbi Yehoshua says: So Israel would not say: The blows have ceased; He has no others to bring upon us, the verse states: “If after these [ad],” if there are more [od] of these, He has other [punishments] and more like these to bring [upon you]. “I will punish you further, seven ways for your sins” (Leviticus 26:18) – You violated seven transgressions before Me; come and accept upon yourselves seven punishments. You violated seven transgressions before Me, so Jeremiah comes to recite lamentations over you which are seven alphabetic [acrostics], eikha.¹¹³The book of Lamentations contains three alphabetical acrostics, in chapters 1,2, and 4, each beginning with the word eikha. Additionally, chapter 3 contains a triple alphabetical acrostic. Chapter 5 is not written in an acrostic, but since it has twenty-two verses, which are the number of letters in the Hebrew alphabet, the midrash refers to this too as alphabetical in the sense that it corresponds to the number of letters in the alphabet (Matnot Kehuna).