First of all, why would you want to? Your editor wants fresh, exclusive quotes you gathered directly yourself.
But anyway, quoting from others is about COPYRIGHT. Copyright exists to protect you from other writers stealing your writings. And of course it’s there to prevent you stealing material from others.
However the law allows writers to “borrow a bit”. That is, you may quote something (“a bit”) from another writer. If you quote another writer, you are entitled to use a reasonable amount of the other writer’s material without having to ask permission and without having to pay. You may quote from anyone who owns copyright in his or her own words, such as an internet writer, a radio commentator, another journalist, a book author, a songwriter, a poet, and so on.
Similarly, anyone may use a reasonable amount from your writing without asking you, without paying you.
But what is “reasonable”? To this question, I always reply: “Imagine that YOU are being quoted from an article you had written. If another writer used two sentences from your article you would enjoy being considered as someone who was WORTH quoting. But if the other writer wrote a 40-paragraph story and 20 of those paragraphs were straight out of your article, verbatim, you’d be furious! You’d feel that wasn’t reasonable, that your material was being used to fill the other writer’s space.”
Remember this: the law allows any writer to quote from any other writer’s work, without asking and without payment PROVIDED that the original writer is named and the work is “sourced”. That is, the book or publication, etc, is identified. And the amount used must be “reasonable”. So, when YOU take something from another writer and use it in your article, be sure to not use an UNreasonable amount.
What is “reasonable” or “unreasonable” must be judged by you. There are no numerical rules like “no more than 1.17%” or “up to 37 words only”. It’s a matter for your judgment. But as I say, start by thinking of someone quoting from your hard-worked writing and what you’d consider “reasonable” to take (unasked, unpaid) from what you had created.