1)
What is the meaning of "va'Yoda Bahem"?
1.
Rashi citing Targum Yonasan: He broke [the people] with [the thorns].
2.
Radak, based on our text of Targum Yonasan: He broke [the people] on [the thorns]. This is like "v'Ydu'a Choli" (Yeshayah 53:3), an expression of breaking.
3.
Radak: He made them know their sin via thorns.
4.
Malbim: He made Anshei Sukos know (their sin, of denying food to the hungry) through them (the officers; he commanded them to afflict Anshei Sukos via thorns).