Why does it say "va'Yis'halchu mi'Goy El Goy"?
'Rashi' (19-20): They were not even settled in one place, rather, they wandered, and even so, Hashem promised the land to them.
Rashi (Tehilim 105:13), Radak: Each of the Avos was exiled from being a stranger in one place to being a stranger elsewhere.
Radak (Tehilim 105:12-13): Hashem put Emunah in their hearts; even though they needed to go from Eretz Kena'an to Egypt and Eretz Pelishtim, they did not resent Hashem's ways.
Why does it add "mi'Mamlachah El Am Acher"?
Radak (Tehilim 105:13): The matter is repeated in different words.
Malbim (Tehilim 105:13): Goyim are collections without a king. Amim are collections with a king. When they went from Goy to Goy, He did not let a man oppress them. When they went from Mamlachah to another Am, He rebuked kings about [mistreatment of] them (verse 21).
