How does " 一切" mean all/entire?


This word contains 一 "one" plus 切 "to cut" .. so how would this mean
all/entire? ... I searched before coming here and found something
[https://kanjiportraits.wordpress.com/2016/10/23/the-kanji-刀切窃初分雰紛契喫潔-刀-sword-
knife-to-cut/](https://kanjiportraits.wordpress.com/2016/10/23/the-
kanji-%E5%88%80%E5%88%87%E7%AA%83%E5%88%9D%E5%88%86%E9%9B%B0%E7%B4%9B%E5%A5%91%E5%96%AB%E6%BD%94-%E5%88%80-sword-
knife-to-cut/) .. they explained that as " When there is nothing left as if it
were a cut off, it meant “all.” ".. So is this explaination right? (I mean the
explaintion in the site for why this kanji means "all") and if not then what
the right explaination for why kanji 切 means "all"

