Still speaking of the feast we have read about thus far, that occurred when Samson married, the Bible seems to make an incidental reference to seven. This was not an Israelite feast, and the Bible makes nothing of the feast lasting seven days,

Now she had wept on him the seven days while their feast lasted. And it happened on the seventh day that he told her, because she pressed him so much. Then she explained the riddle to the sons of her people. So the men of the city said to him on the seventh day before the sun went down: 

“What is sweeter than honey? 
And what is stronger than a lion?”

And he said to them: 

“If you had not plowed with my heifer, 
You would not have solved my riddle!” 
(Judges 14.17–18) 

Do you see any significance to this reference to seven?