Edit: naturally, there is a strong bias for older comments in the list.

Code I use:

    <script>
		
		  $(document).ready(function() {
  var lasthours = "";
    
    $("#refresh").on("click", function() {
      
      var html = "";
      var url = "https://hn.algolia.com/api/v1/search?tags=comment&numericFilters=points>120&page=";
      var page = Math.floor(Math.random() * (20)) + 1;
      url += page.toString();
       
      var position = 0;
      position = Math.floor(Math.random() * 20);
   
      
    $.getJSON(url, function(json) {
      
        var hits = json.hits;
        
        var html = "<p>"+hits[position].comment_text+"</p><p>Story: <a  target='_blank'  href='"+hits[position].story_url+"'>"+hits[position].story_title+"</a><br><a  target='_blank'  href='https://news.ycombinator.com/item?id="+hits[position].story_id+"'>comment by "+hits[position].author+"</a></p>";
        
    $("#quote-text").html(html);
    });
    });
  });
		
		</script>