Why does it say "ba'Meh Kocho Gadol uva'Meh Nuchal Lo"?
Malbim: They asked two matters. (a) What is the Segulah for his strength; then, they can try to negate it. (b) Even if it is natural strength, how can he be tied up? Some have strength in it their arms, but not in their feet, and he can be bound via his legs or another part of the body where he is not strong. 1
Pelishtim saw that the ropes around his arms melted (15:14). He can reach with his hands to any part of his body to break any ropes! Perhaps no one lived to tell about the ropes melting (all who saw were among the 1000 that he killed then), and no one saw him uproot the doors of Azah (perhaps he kicked them down) and he did not tell how he split the lion. This is difficult. (PF)
Why did they say "v'Asarnuhu Le'anoso"?
Malbim: They promised her not to kill him. They fulfilled this; they only gouged out his eyes.
Why does it say "v'Nitan" with a Patach under the Tav?
Chomas Anach: We are leaders of the nation. Our word and promise is as if the money was already given to you.