The original meaning means that the author thinks during the day and dreams at night. National security affects the author Lu You's heart all the time, so he has the dream of "Iron Horse Glacier".
"Iron horse is you, ice is you", which shows that these things have entered the author's "dream". Why did you appear in my dream? Because you are the person I look forward to day and night!
Extended data
Two Storms on November 4th is a seven-character quatrain written by Lu You, a poet in the Southern Song Dynasty. It was made in November of the third year of Shao Xi (1 192). At that time, the author had retired to his hometown.
The first poem is about the heavy rain and where the poet is. The second poem shows that Lu You is resisting Japan, which is the glory of this country. However, the poet's mind was empty and he was not valued by the court. He can only retreat to Shan Ye and rely on his dreams to restore the national ideal of the Central Plains. The emotion is profound and tragic, which reflects the poet's patriotic enthusiasm.
The second poem profoundly expresses the author's ambition to recover the country and serve the motherland and the unswerving spirit of "being old without losing" in the way of "dreaming", and shows the reader the absolute loyalty of the poet.
Lying in the dead of night listening to the wind and rain is followed by two sentences. I can't sleep at night because I want to. If I can't sleep, I can feel the wind and rain of nature more truly. From the storms of nature, I thought of the stormy country. From that stormy country, I naturally think of the storm of war and my youthful military life. In this way, while listening and thinking, I turned to a special dream-"Iron Horse Glacier". "Dreaming" reflected the sadness of political reality: the poet wanted to serve the country but was rejected, so he could not kill the enemy, and the feeling of defending the enemy could only be shaped in his dream. The Dream of Tiema Glacier is the result of the poet's thinking day and night, which vividly expresses the poet's heroism. This is also the aspiration of a generation of people with lofty ideals and the national justice of the Southern Song Dynasty.
References:
Baidu Encyclopedia-1 1 Two storms on April 4th.