Lamentations 4:3

Even the sea monsters draw out the breast, they give suck to their young ones: the daughter of my people is become cruel, like the ostriches in the wilderness.

Lamentations 4:3-10 sets forth the severe suffering of the Babylonian calamity, the tribulation that came upon the Jews under the Babylonians.
Verse 3 draws a sharp contrast between even sea creatures and wild animals that draw out the breast to nurse and give suck to their young, and the cruelty and distress fallen upon the people.
The daughter of my people is Jerusalem, God's own people, now become cruel.
That cruelty is likened to the ostriches in the wilderness, which neglect their young.

The anguish so described is comparable to the great tribulation spoken of in Matthew 24.
Yet the record of suffering under Babylon shows that the later destruction of Jerusalem was not itself the greatest tribulation ever of which Matthew 24 speaks.
The charge of cruelty also reaches the heartless wholesale slaughter of birds killed for their plumage to gratify pride and fashion.