What does Judges 14:13 mean?
Samson has been assigned thirty Philistine men as companions for his week-long marriage wedding feast (Judges 14:1–3, 10–11). It's unclear whether these men are meant as drinking companions, security, or simply traditional guests. At some point on the first day of the celebration, Samson has challenged them with a wager (Judges 14:12). He has offered to provide each man a linen garment and a change of outer clothes, if they can solve his riddle—and they have seven days to solve it.If they cannot solve his riddle, they will each give him one linen garment and change of clothes. If Samson loses, he will be obligated to provide thirty sets of clothes, which would be an expensive penalty. Clothing was much costlier in the ancient world than in most modern cultures. The Philistine men eagerly agree; at first, this seems like moderate stakes for the Philistines. Even if they lose, each man only needs to come up with one change of clothes. That's not cheap, but neither is it outrageous. Further, the men likely assume that between the thirty of them, they should be able to resolve the mystery within in the week. It's possible the men believe Samson is being extravagant: that he's offering them gifts with the added entertainment of figuring out a clever riddle.
Brash Samson doesn't plan on losing. What he will present is not so much a "riddle" as a poetic explanation of a secret event (Judges 14:14)—so he has no reason to think anyone could ever guess the answer.