But it happened after a while, in the time of wheat harvest, that Samson visited his wife with a kid; and he said, I will go in to my wife into the chamber. But her father wouldn't allow him to go in.
"I shall be blameless, when I do them mischief"  (Judges 15:3).  This was Samson's blunt rejection of the offer of her younger sister, and it was also the statement of his intention to take vengeance on all the Philistines.  Neither Samson nor the Philistines knew anything about a "Golden Rule."  The father-in-law had indeed avoided what he considered a disgrace to his family, but he had failed to take into account the kind of man Samson was.  He had a just cause for revenge, and he would certainly take advantage of it.  The father-in-law's offer of the younger sister was an admission of the injustice done to Samson.