Student or Learner
Purely grammatically speaking, phrase is not a sentence (a unit within one or without).
However, it also contains a rhetorical aspect which indicates a way of saying something.
For example, He used a phrase like, "you have to be cruel to be kind."
or "catch phrases" are also often sentences.
When we want to quote/cite something from a book, is it okay to call them phrases?
I find this aspect of phrase blurry.
Not a lot of people will care, but generally speaking if the group of words you are quoting contains a finite verb, don't call it a phrase.
Find another word, like
'He used the expression "You have to be cruel to be kind".'
'As the saying goes: "Waste not, want not".'
'In the words of the proverb: "A rolling stone gathers no moss".'
Catchphrase is all one word, with a separate definition.