To whom does "Goyim" refer?
Rashi: Pharaoh Melech Egypt.
What is the meaning of "va'Yishme'u Elav Goyim"?
Radak: Pharaoh, who was in Eretz Yisrael Chamas, heard that [Yeho'achaz] invaded Egypt 1 , and they seized him when he returned from there.
Malbim: Pharaoh cam against him.
Either he explains "va'Yishme'u" to mean 'he paid attention to', or he explains "Elav" like Alav (he heard about him). (PF)
What is the meaning of "b'Shachtam Nispas"?
Rashi: They dig holes and cover them with straw, and the Chayah falls inside. Radak - this is like "Koreh Shachas" (Mishlei 26:27).
Radak citing Targum Yonasan: He was caght in his fortress.
What are "Chachim"?
Rashi: They are like iron rings. They pierce his nose (the wall between the nostrils), and pull him via the rings.
Radak, Targum Yonasan: They are iron chains.
