What does it mean that a cloud has risen between the light of heaven and me, hiding his city from my melancholy heart?

Clouds in the sky sometimes cover the sun, so that I can't see Chang 'an, and I can't help but feel very sad.

These two sentences have profound implications: "Floating clouds" refer to traitors and "Sun" refers to emperors. This poem implies that the emperor has been surrounded by traitors and state affairs have become corrupt. These two poems also express the poet's deep feeling that he can't serve his country.