T.S. Eliot's The Waste Land Wiki

The change of Philomel, by the barbarous king

So rudely forced; yet there the nightingale

As mentioned above, this part of the poem is an allusion to the tale of Philomela being raped by King Tereus, took revenge on him and finally escaped by turning into a nightingale. Philomela turning into a nightingale was a desperate attempt to free oneself from the ultimate prison of love and brutality. Trust in love and humanity was lost, hope was gone, nothing but a bleeding wound (inside and out) was left.   

Filled all the desert with inviolable voice

And still she cried, and still the world pursues,

Jug Jug” to dirty ears.

The fact that Philomela was turning from a human being into an animal resembles the overwhelming exasperation of hers, result in the form of mental breakdown, into something subhuman, with meaningless and aggressive sound made only at night. She was unable to express her inner-self to the world but instead had to keep lamenting about the tragic incident on her own.

And other withered stumps of time

Were told upon the walls; staring forms

Leaned out, leaning, hushing the room enclosed.

Alike Philomela being a nightingale and had her stories unheard, the tapestries on the wall (in this case were being referred to as “withered stumps of time”) of the 'castle' shared the same fate. They each had their own story and that was dying to be told (probably to the woman) as they kept “leaning” toward, trying to shift away from their century-old positions. But still, the woman heard nothing. Just like no matter how hard and agonizing may the nightingale sang, the people comprehended nothing. Was it because the tapestries and the nightingale failed to deliver themselves? Or because the society, the people, us, had lost the ability to understand, and further emphasize their most desperate call.

Chapter 3 - The Fire Sermon 

Twit twit twit
Jug jug jug jug jug jug
So rudely forc’d.  

These lines, in chapter 3 of the poem, are a reference to Philomel. This is the second corrupted sex story, after the reference of To His Coy Mistress, that the author brought into The Fire Sermon. Just like how water lost its symbolism of life in the first part, the author showed us that love has also lost its meaning. Tereus took advantage of Philomel and her sister. He lied to both of them not because he loved them, but because he wanted to satisty his sexual desire. And this theme is displayed through out the chapter The Fire Sermon.