1)
Why does it say "Al Yedeihem"?
1.
Rashi: This does not teach about location. Rather, the donkeys grazed via [what the cattle plowed]. 1
2.
Rashi (from Bava Basra 15b): He tasted [Berachah] like the world to come. He seeded right after plowing, and the donkeys ate immediately [fodder] from the furrow.
3.
Ibn Ezra: This is their place, like "v'Yad Tihyeh Lecha."
1
Malbim: The plunderers did not come at night, rather, during the day, when the donkeys grazed and the cattle plowed.
