The poet used "grass" to compare "Song Qing" and "Li Anlin" to compare "single wood", which shaped the tall image of Song Qing who was not afraid of the cold and tall (outstanding and independent).
Please analyze the relationship between the conclusion of the poem ("What is the dust in my dream") and the above.
The first half of the poem praises Song Qing's noble quality, expresses the author's appreciation of Song Qing, and draws the conclusion that life is like a dream and the world (worldly life and official career) is like a dust net, which shows his cherish and expectation for Song Qing's loyal and noble personality (independence and freedom).
Or: Poetry is a token (the first half is written about pine trees), expressing one's ambition (summarizing one sentence to show one's interest), and the immortal pine tree is a symbol of the poet's unyielding character, which also shows the author's pursuit of this extraordinary interest.