“Fare thee well, and if for ever
Still for ever fare thee well.”
                                
                                
                                
                                
                            
                                        
                                         Fare Thee Well http://readytogoebooks.com/LB-FTW46.htm, st. 1 (1816). 
Context: Fare thee well! and if forever,
Still forever, fare thee well:
Even though unforgiving, never
'Gainst thee shall my heart rebel.