1)
Why did he command Giborim to tie them? Did he think that they will resist being cast to the fire?
1.
Rashi: Yes, for he saw that they answered him harshly. He thought that they are Giborim.
2.
Malbim: They said that Hashem will save them from his hand, He wanted to Giborim to stand against Divine power. He thought that this is possible, like Pelishtim said "be men and fight with Elokim"!
