It means that the other party's residence is not far away from Penglai Mountain, but there is no way to get there and it is out of reach. I hope there will be a messenger like a blue bird who will diligently visit my lover for me.

It comes from a love poem "Untitled: It's Hard to Say Goodbye When We Meet" written by Li Shangyin, a poet of the Tang Dynasty, based on the theme of the separation of men and women.

The whole poem is as follows:

It is difficult to say goodbye when we meet, the east wind is powerless and the flowers are withered. The spring silkworm's silk will not be used up until it dies, and the wax torch will not dry until it turns to ashes.

When you look into the mirror at dawn, you are worried about the clouds on your temples. When you sing at night, you should feel the cold moonlight. There is not much way to get to Pengshan, and the blue bird is diligent in visiting. ?

The translation is as follows:

It is difficult to meet, and even more difficult to say goodbye, not to mention in this late spring season when the east wind is weak and the flowers are withered. A spring silkworm spins a cocoon and spins out all its silk only when it dies. A candle's tear-like wax drips dry only when it is burned to ashes.

When I dress up and look in the mirror in the morning, I am only worried that my cloud-like hair on my temples will change color and my appearance will no longer look the same. If you spend a long night alone reciting poems and not falling asleep, you will definitely feel the cold moon encroaching on you. Penglai Mountain is not too far away from here, but there is no way to get there. I would like to ask an envoy like a blue bird to visit it for me diligently.

Notes are as follows:

Untitled: Since the Tang Dynasty, some poets often use "Untitled" as the title of their poems when they are unwilling to indicate a title that can express the theme.

The east wind is powerless and the flowers wither: This refers to the late spring season when the flowers wither. East wind, spring breeze. Withered, withered.

Extended information:

This poem is filled with pain, disappointment, lingering, and persistent emotions from beginning to end. Every couplet in the poem has this emotional state. reflection, but the specific artistic conception of each couplet is different from each other.

They repeatedly express the complex emotions that run through the whole poem from different aspects. At the same time, they are closely connected with each other and vertically reflect the psychological process with this complex emotion as the content. This kind of lyricism, continuous and subtle, successfully reproduces the deep feelings in the heart.

Sentences 1, 3, 4, and 5 in the poem can all be found in similar descriptions from Li Shangyin’s previous poetry creations. Under the influence and inspiration of predecessors' creations, poets have inherited and learned from them.

However, he did not simply imitate his predecessors, but took a big step forward with high creativity, transforming the original relatively simple expression methods into more twists and vivid, and used them to Reflecting richer and deeper thoughts and feelings, it has actually shed its old form and become a new creation. ?

Baidu Encyclopedia - Untitled·It’s hard to say goodbye when we meet