Edom Are To Be Punished For Their Part In Jerusalem's Downfall And For Taking Possession Of Southern Judah. Whilst There Was Hope In The Future For Zion, There Would Be None For Edom (Lamentations 4:21-22).
Added to the trials through which Jerusalem and Judah was going as just described was the fact that their neighbours Edom had taken the opportunity to seize land in southern Judah as a reward from Nebuchadrezzar for supporting him against Judah. Their king had failed them, but even worse their neighbours had proved treacherous. But this enabled the prophet to introduce a message of hope for Zion, while at the same time assuring Edom of the punishment that awaited them.
(Shin) Rejoice and be glad, O daughter of Edom,
Who dwells in the land of Uz,
The cup will pass through to you also,
You will be drunk, and will make yourself naked.
The opening words are sarcastic. Edom was rejoicing at having gained at the cost of their neighbours, for they had supported the Babylonians and had been well rewarded by Nebuchadrezzar, being given land in southern Judah. See in this respect Psalms 137:7 (note their unholy glee at the fate of Jerusalem); Obadiah 1:11-14. Well let them rejoice while they can. For shortly the cup that Jerusalem had drunk would be passed to them. They too would drink of the cup of suffering and of God's wrath, and they too would become drunk and naked (see Jeremiah 25:15-17).
‘Who dwell in the land of Uz' an ancient name connected with Edom. For ‘Uz' see Genesis 10:23; Job 1:1; Jeremiah 25:20.
(Tau) The punishment of your iniquity is accomplished, O daughter of Zion,
He will no more carry you away into captivity,
He will visit your iniquity, O daughter of Edom,
He will uncover your sins.
The lament ends with an unexpected assurance to Zion of YHWH's continued watch over them, and a warning to Edom of what lay in store for them. Whilst Zion could still expect God finally to show mercy, for Edom there was no hope (Ezekiel 25:12-14; Joel 3:19-21). The contrast is intended to bring out the wonder of God's goodness towards Zion over against the judgment coming on their enemies.
Having described in detail the ordeal through which Jerusalem has gone, the prophet now assures them that they have reached the bottom of the barrel. They can sink no further. The punishment of their iniquity has been accomplished (compare Isaiah 40:1-2) and YHWH had no plans for further judgments on them. The assumption must be that from now on He intended to smile upon them. Their past sins at least had been dealt with in full measure.
It will be otherwise for Jerusalem's enemies. Edom would be visited (dealt with in judgment) for their iniquity, and their sins would be uncovered, resulting in the necessary punishment of them. It was the opposite of having their sins ‘covered'. The implication is that it would be different for Jerusalem, who would experience the mercy of God, although no detail is given.