Tough question.
Although in this series we have tended to concentrate on literary and exegetical issues in an attempt to understand the interpretative methodology of Chazal, it is undeniable that many midrashim deal with important theological issues. Unfortunately, it is rare for a midrash to actually spell out the issue under consideration. Uncovering the theological problem is, of course, indispensable as the first step to understanding the proposed solution. It goes without saying that without that step the problem and the solution will likely escape comprehansion.
Let us take a look at a difficult passage found in Tanchuma ( Bachukisai, 2). First, let's present the problem in words of Avraham Ibn Ezra (Tehilim 89, 48)
"This author speaks of Israel in their exile for it is apparent to all that generation after generation passes but there is no redeemer. How long shall one who hopes, long, for one's days are short…. Why have you created us; we are nothing… The meaning is that every Jew anguishes in his exile that he will die and not see Hashem's salvation".
The aforementioned Psalm presents an impassioned plea. It starts with reviewing facts of history, G-d's deliverance of the Jewish people form Egypt and His promise to David to keep faith with the Davidic line no matter what their shortcomings.
Maschil of Ethan the Ezrahite.
2 I will sing of the mercies of HaShem for ever; to all generations will I make known Thy faithfulness with my mouth.
3 For I have said: 'For ever is mercy built; in the very heavens Thou dost establish Thy faithfulness.
4 I have made a covenant with My chosen, I have sworn unto David My servant:
5 For ever will I establish thy seed, and build up thy throne to all generations.' Selah
6 So shall the heavens praise Thy wonders, O HaShem, Thy faithfulness also in the assembly of the holy ones.
7 For who in the skies can be compared unto HaShem, who among the sons of might can be likened unto HaShem,
8 A G-d dreaded in the great council of the holy ones, and feared of all them that are about Him?
9 O HaShem G-d of hosts, who is a mighty one, like unto Thee, O HaShem? And Thy faithfulness is round about Thee.
10 Thou rulest the proud swelling of the sea; when the waves thereof arise, Thou stillest them.
11 Thou didst crush Rahab, as one that is slain; Thou didst scattered Thine enemies with the arm of Thy strength.
12 Thine are the heavens, Thine also the earth; the world and the fulness thereof, Thou hast founded them.
13 The north and the south, Thou hast created them; Tabor and Hermon rejoice in Thy name.
14 Thine is an arm with might; strong is Thy hand, and exalted is Thy right hand.
15 Righteousness and justice are the foundation of Thy throne; mercy and truth go before Thee.
16 Happy is the people that know the joyful shout; they walk, O HaShem, in the light of Thy countenance.
17 In Thy name do they rejoice all the day; and through Thy righteousness are they exalted.
18 For Thou art the glory of their strength; and in Thy favour our horn is exalted.
19 For of HaShem is our shield; and the Holy One of Israel is our king.
20 Then Thou spokest in vision to Thy godly ones, and saidst: 'I have laid help upon one that is mighty; I have exalted one chosen out of the people.
21 I have found David My servant; with My holy oil have I anointed him;
22 With whom My hand shall be established; Mine arm also shall strengthen him.
23 The enemy shall not exact from him; nor the son of wickedness afflict him.
24 And I will beat to pieces his adversaries before him, and smite them that hate him.
25 But My faithfulness and My mercy shall be with him; and through My name shall his horn be exalted.
26 I will set his hand also on the sea, and his right hand on the rivers.
27 He shall call unto Me: Thou art my Father, my G-d, and the rock of my salvation.
28 I also will appoint him first-born, the highest of the kings of the earth.
29 For ever will I keep for him My mercy, and My covenant shall stand fast with him.
30 His seed also will I make to endure for ever, and his throne as the days of heaven.
31 If his children forsake My law, and walk not in Mine ordinances;
32 If they profane My statutes, and keep not My commandments;
33 Then will I visit their transgression with the rod, and their iniquity with strokes.
34 But My mercy will I not break off from him, nor will I be false to My faithfulness.
35 My covenant will I not profane, nor alter that which is gone out of My lips.
36 Once have I sworn by My holiness: Surely I will not be false unto David;
37 His seed shall endure for ever, and his throne as the sun before Me.
38 It shall be established for ever as the moon; and be stedfast as the witness in sky.' Selah
Suddenly the tone changes and lament, in fact, accusation replaces it.
39 But Thou hast cast off and rejected, Thou hast been wroth with Thine anointed.
40 Thou hast abhorred the covenant of Thy servant; Thou hast profaned his crown even to the ground.
41 Thou hast broken down all his fences; Thou hast brought his strongholds to ruin.
42 All that pass by the way spoil him; he is become a taunt to his neighbours.
43 Thou hast exalted the right hand of his adversaries; Thou hast made all his enemies to rejoice.
44 Yea, Thou turnest back the edge of his sword, and hast not made him to stand in the battle.
45 Thou hast made his brightness to cease, and cast his throne down to the ground.
46 The days of his youth hast Thou shortened; Thou hast covered him with shame. Selah
47 How long, O HaShem, wilt Thou hide Thyself for ever? How long shall Thy wrath burn like fire?
48 O remember how short my time is; for what vanity hast Thou created all the children of men!
49 What man is he that liveth and shall not see death, that shall deliver his soul from the power of the grave? Selah
50 Where are Thy former mercies, O L-rd, which Thou didst swear unto David in Thy faithfulness?
51 Remember, L-rd, the taunt of Thy servants; how I do bear in my bosom the taunt of so many peoples;
52 Wherewith Thine enemies have taunted, O HaShem, wherewith they have taunted the footsteps of Thine anointed.
53 Blessed be HaShem for evermore. Amen, and Amen.
In wholly unprecedented fashion, the psalmist accuses G-d of violating his promise and… he provides no justification or answer [1]. This is not merely questioning or cry for an explanation - it goes beyond anything else in Tanach in boldness and daring. The theological issue is, of course, familiar to us - did the destruction of the Temple and scattering of the Jewish nation constitute voiding of the original covenant. What made the question more difficult is the undeniable fact that the Pentateuch does not seem to contain any prediction of this event [2]. Here is a reaction of one of Ibn Ezra's contemporaries (89,2).
"There was in Spain a great scholar to whom this psalm was difficult. He would not read it and could not hear it read because this author spoke harshly against Hashem."
To rephrase, the length of the exile and the violation of terms of the covenant with David present very serious theological issues [3].
The midrash Tanchuma (Bachikosai 2) asks and answers this question [4].
So it states: G-d will reject them for they did not obey Him (Hosea 9 ). The Holy One Blessed Be He said: I said that they shall be planted upon their land. When? If they walk in my ways. You did not do so but Children of Israel ascribed to Hashem things that were not so (Kings III, 17 ). You blamed me for what was not 'so' and I also placed upon you that which was not 'so' . I also placed upon you things that were not written in My Torah - Also every illness and every wound which is not written in this book of Torah (Deut. 28 ).
What are the things that you did that are not 'so' ? Isaiah said: They abandoned G-d, rejected the Holy One of Israel (Isiah 1 )…. With your sins you have made me merciless and turned the quality of Mercy into the quality of Justice., as it says, G-d became and enemy, he destroyed Israel (Lamentations 1 )…. Therefore Hosea said: What caused all this to happen to you? Because you did not obey, G-d has rejected you (Hosea 9 )
The midrash suggests that Jews went beyond the parameters of the original covenant when they "did not obey" and therefore G-d was free from His promises as well. Not only that, He acted justly by voiding his side of the violated agreement, as predicted in the verse of Deuteronomy 28.
This passage is a good example of a "theological" midrash. These passages tend to be among the most difficult, for one needs significant grounding in history, philosophy, theology and Jewish Thought to identify the issue under discussion and the answer being provided.