"The inn links up at once in his memory with a quotation"

 The quotation Freud's patient recalls is from German poet Ludwig Uhland's ode to nature Einkehr ('Stop-over'). 

From 'The Songs and Ballads of Uhland', as translated by W. W. Skeat (original 1815)

 

A kind and gentle host was he  

With whom I stayed but now;  

His sign a golden apple was  

That dangled from a bough.

   

Yea! 'twas a goodly apple-tree                        

With whom I late did rest;  

With pleasant food and juices fresh

My parching mouth he blest.  

   

There entered in his house so green  

Full many a light-winged guest;               

They gaily frisked and feasted well  

And blithely sang their best.  

   

I found a couch for sweet repose

Of yielding verdure made;  

The host himself, he o'er me spread  

His cool and grateful shade.                       

 

Then asked I what I had to pay,  

Whereat his head he shook;  

blest be he for evermore  

From root to topmost nook!