In the final stanza of A Red, Red Rose by Robert Burns, there may be some effects from the impending separation. The most likely effect might be that there love will have to be patient a wait for the returning of her lover. Their love may fade away and become blurred because of time and distance.
The separation might be because her lover had to go to the war or had to leave for some time in order to work and make some money. Whatever the reasons are, they're external not concerning their relationship as a couple.