polymorphic help

With the help of some devs. I was able to list down commends of a
specific deal using the "def comments" method in the deal model
class.

However, what I also need is to display the owner/user who made the
comment via the @deal.comments loop. For example, something like this
would be ideal:

<% @deal.comments.each do |comment| %>
  <%=h comment.comment %>
  <%=h comment.user.first_name %>
<% end %>

Here is my actual code so far. I believe the key is to edit the "def
comments" method in the deal model class to include the user model or
something like that. Any help is appreciated...