http://revach.net/article.php?id=2281

Section: Stories   Category: Story Corner
One Playgroup and Three Weddings
An avreich in Rechasim had the good fortune of having two sets of twins born to him one after the other, in addition to his older children.  However, the good fortune was accompanied by the reality of having four extra mouths to feed in a short amount of time.  His wife decided to open a gan (playgroup) in their apartment to help support the family.  Their apartment was on the ground floor with an adjoining courtyard, so it was an ideal setting for a gan.  They asked permission from the neighbors, who were aware of their difficult financial situation, especially since the birth of the two sets of twins, and they all graciously agreed.  Each one gave permission in writing for the opening of the gan.
    
All the preparations were going smoothly, until one of the neighbors decided to retract his permission, citing two reasons for his decision.  First of all, his wife suffered from high blood pressure, and he was worried that the noise from the gan would negatively affect her health.  Secondly, three of his children had strayed from the Torah path, and he was making all kind of efforts to influence them to return to a Torah lifestyle.  He feared that if his children would see that the charedi neighbors were not considerate of their mother’s high blood pressure, they would be very angry, and there would be no hope of them returning to a Torah life.  
    
The avreich was very distressed by the neighbor’s decision, and he consulted with one of the rabbanim in the city.  The Rav paskened that even if the neighbor’s wife suffers from high blood pressure, he’s forbidden from retracting his original agreement, since his agreement was considered a neder.  The avreich told the neighbor about the Rav’s psak, and the neighbor requested to speak with the Rav himself.  The avreich took him to the Rav, and the Rav repeated his psak that it was forbidden for him to retract his agreement.  However, the Rav also had something additional to say.  He took out a bottle of wine and said to the man, “If you grant permission for the gan, you’ll be zochech to pour from this wine at the chasunos of your three children, after they return with a teshuvah shelaima!”

When the neighbor heard these words from the mouth of the Rav, he granted his permission again for the opening of the gan, and the two neighbors left in peace.  As the years passed, the Rav’s words were fulfilled completely.   (Barchi Nafshi)