I'm slightly confused by using the word 'knowing' as a noun. Longman Dictionary of Contemporary English (5th edition) says that 'knowing' can be used only as an adjective. But, for example, Merriam-Webster Dictionary says that it can be a noun. I've always thought that we should use 'knowledge' instead of 'knowing', and that the last one doesn't exist as a noun at all. But recently I faced with such Richard Feynman's quote: "I learned very early the difference between knowing the name of something and knowing something". So, is using the word 'knowing' as a noun good and common for standard English?
As noted in the comments, the sentence given in the question is a simple use of a gerund.
Nevertheless, the Oxford English Dictionary lists five different historical meanings for the word 'knowing' used as an independent noun with a separate sense. Most are obsolete. One is the use of 'knowing' for 'knowledge,' (as in phrases like carnal knowing), though that usage is pretty rare nowadays.
Another idiomatic sense is still sometimes encountered in phrases like "there is no knowing," e.g., "There's no knowing what he might do if he found out." This idiom apparently comes from an archaic sense where 'knowing' refers to being informed or aware of something, usually associated in older texts in phrases like "the knowing of X."
In short, aside from a few idioms, 'knowing' is usually only used as a gerund in modern English, with the same meaning as the verb.