Nokogiri: how to find a div by id and see what text it contains?

I just started using Nokogiri this morning and I'm wondering how to perform a simple task: I just need to search a webpage for a div like this:

<div id="verify" style="display:none"> site_verification_string </div>

I want my code to look something like this:

require 'nokogiri'
require 'open-uri'

url = h(@user.first_url)
doc = Nokogiri::HTML(open(url))
if #SEARCH_FOR_DIV#.text == site_verification_string
  @user.save
end

So the main question is, how do I search for that div using nokogiri?

Any help is appreciated.