How give a recommendation letter to my professor when I need it back? Basically, i have asked a professor if he would write a recommendation letter for me and he graciously agreed.

But for some reason, this recommendation letter needs to come back to me because it has to be in my complete application I need to send in the end. (The complete application is a hard copy that needs to be mailed)

Do I mail the professor a hard copy of the recommendation letter with a stamp so he can send it back after he fills it out? If I do this, do i ask him for his address? (its summer now)

Or do I send him an email with the soft copy of the form attached and ask him to print it out and mail it to me?

Thanks!
She or he could write your recommendation letter, and put it in a sealed envelope. Then, you submit your application with the sealed envelope.