is an expression that has two primary purposes in Japanese. To convey that there is ‘no need for (A)’, or that ‘(A) never happens’. In these cases, (A) is a verb that will appear directly before こと. ことはない
is often used to reassure someone that something will not come to pass.
In this expression, the 副助詞（ふくじょし） (adverbial particle) は is working to present (A) as the extent (a regular role of adverbial particles), while the 形容詞（けいようし） ない negates that extent. This negation is up to interpretation, with the literal meaning simply being ‘There is no (A)’.
There is no need to rush that much. We still have a lot of time, so it is okay if you pace yourself.
Ever since I fought with my parents 10 years ago, I have not talked to them.
This structure is very different to たことがない, which presents a single instance of something not having happened. As opposed to the 格助詞（かくじょし） (case marking particle) が, は presents the verb/verb-phrase as a topic itself in non-past form, highlighting its non-existence. Due to this, ことはない
can imply that (A) is unthinkable, or even impossible.
There has never been a time where I worried that much.
There is no need to worry that much.