I'm sorry that my answer was not accurate enough. In classical Chinese, the word "Shi Shi" was not usually used to express causality because it had been widely used in modern Chinese and was often used to express causality. In classical Chinese, more precise expressions such as "hence","hence","hence", etc. were usually used. If you need to express causality, you can use more explicit expressions such as "this is also","this is also that", etc.