title: Command Validation in DDD with CQRS
body: <p>I am learning DDD and making use of the CQRS pattern.  I don't understand how to validate business rules in a command handler without reading from the data store.  </p>
  
  <p>For example, Chris wants to give Ashley a gift.</p>
  
  <p>The command might be GiveGiftCommand.  </p>
  
  <p>At what point would I verify Chris actually owns the gift he wants to give?  And how would I do that without reading from the database?</p>