seo – How can I check if some textual content is used elsewhere?

I have ordered a blog post for my website, which was written by someone else. Now I've received the text from the original author, but I'm a little worried about it copying the content from other websites, which will have a pretty good SEO result negative for me.

My question is: how can I be sure that he has not copied the content ordered elsewhere? Is there some kind of tool or something? Thank you.