The Book of Lamentations is Jeremiah's grieving for Israel as he considers the third and fourth generations/ages of their existence and the devastation and desolation of Jerusalem. The period of this desolation and devastation is found in a reference to Exodus 20:4-6 in Jeremaiah 5:7: -
Jer 5:7: - Our fathers sinned and are no more, But we bear their iniquities.
where Exodus 20:4-6 states this: -
Exodus 20:4-6: - 4 "You shall not make for yourself a carved image — any likeness of anything that is in heaven above, or that is in the earth beneath, or that is in the water under the earth; 5 you shall not bow down to them nor serve them. For I, the Lord your God, am a jealous God, visiting the iniquity of the fathers upon the children to the third and fourth generations/ages of those who hate Me, 6 but showing mercy to thousands, to those who love Me and keep My commandments.
This is confirmed in Lam 5:19-22:-
Lamentations 5:19-22: - 19 You, O Lord, remain forever;
Your throne has continue for two generations/ages.
20 Why do You forget us for such a long period of time (where the vanishing point is beyond our ability to comprehend),
And forsake us for so long a time?
21 Turn us back to You, O Lord, and we will be restored;
Renew our days as of old,
22 Unless You have utterly rejected us,
And are very angry with us!
Hosea also expressed the same sediment as Jeremiah did in Hosea 6:1-3: -
Hosea 6:1-3: - A Call to Repentance
6:1 Come, and let us return to the Lord;
For He has torn, but He will heal us;
He has stricken, but He will bind us up.
2 After two days {within God’s timeframe of reference (See note 1 below} He will revive us;
On the third day {within God’s timeframe of reference} He will raise us up,
That we may live in His sight.
3 Let us know,
Let us pursue the knowledge of the Lord.
His going forth is established as the morning;
He will come to us like the rain,
Like the latter and former rain to the earth.
Note 1: - The length of time of a Day within God’s timeframe of reference, within mankind’s timeframe of reference is, in my understanding, a period of 1,024 {solar} years.
The Book of Lamentations is Jeremaih's lament over Israel for when Israel will be scattered to the four corners of the earth because of their continual idolatrous worship during the first and second generations/ages of their existence when God will not look upon Israel until the visitation of the iniquities of the fathers is completed.
Shalom