The third joint is not only the immediate reality, but also the poet's expectation of the situation. The bamboo branches stand tenaciously, and the light is exposed to the high mountain corners, where the wind blows. Here, the poet's careful observation of rain changes shows that he is highly concerned about reality. Although the violent clouds and rain covered everything, everything in the rain did not completely yield, and the situation was not dark. There is also unyielding resistance in the cloudy rain curtain, and there is also a chance of life in the shaky crisis (here mainly refers to the active anti-gold move of Changsha Shoushuaiyan at that time).
The above is taken from Baidu Encyclopedia.