What is the Romance of the Three Kingdoms, Sima Yi-Fu every cloud has a silver lining?

Sima Yi confronted Zhuge Liang in Chencang. Later, Wei Mingdi Cao Rui sent general Cao Zhen to replace Sima Yi, with Cao Zhen as the right general and Sima Yi as the deputy general. It was going to rain at that time, and Zhuge Liang later said that the plum rain would last for a long time, so it was temporarily withdrawn. Chencang is low-lying and will soon be eroded by water, and weapons will rot. Sima Yi's sentence has two meanings. First, I seem to have been demoted now, but the opportunity will come soon, because you are going to die in Cao Zhen. It's not up to me in the end. It's good that you didn't come. When you come, help me establish the prestige of Sima. It's really a good man, which proves that it never rains but it pours. Secondly, Cao Zhen came and Zhuge Liang left, which seems to be a victory. In fact, he will be in big trouble soon, because by then, these weapons will rot. See if you are really with Zhuge, which proves that there are joys and sorrows. Son, is it a blessing in disguise?