What do you mean, "Heaven never shuts one door but he opens another, not for Yao's survival or for Jie's death"? Who said that?

It means that there is a certain law in the operation of nature, and this law will not change because of Yao's wisdom or Jie's tyranny. From Xunzi's book Xunzi's theory of heaven in the Spring and Autumn Period. It completely denies the saying that heaven has a will, and distinguishes the objective laws of nature from the development of human society. This is Xun Kuang's view that "Heaven and Man are separated".

Xunzi was a representative figure of Confucianism in the late Warring States period. He served as a "scholar offering wine" in the famous "Xia Ji Gong Xue" three times. Xunzi extensively absorbed the essence of various thoughts and enriched the ideological content of early Confucianism. On the relationship between man and nature, he emphasized that "nature is constant" on the one hand, and pointed out that "human nature is promising" on the other hand, and put forward the important thought of "using life to control it"

Extended data:

Xun Kuang was Xunzi (a thinker of Zhao at the end of the Warring States Period), (about 365,438 BC+03-238 BC), a native of Zhouyi (now Anze County, Shanxi Province) at the end of the Warring States Period, a famous thinker, writer, politician and one of the representatives of Confucianism.

A famous thinker, writer, politician and one of the representatives of Confucianism, he is known as "Xun Qing". He went to Gong Xue, Xia Ji, the State of Qi for three times, and was later ordered by Lan Ling of Chu (now Lan Ling of Shandong). Xunzi developed Confucianism and advocated the theory of evil nature, which is often compared with Mencius' theory of good nature. It has also made considerable contributions to the collation of Confucian classics.

References:

Baidu encyclopedia-Xunzi's theory of heaven