1)
Where did the Slav fall?
1.
Radak: It was "b'Kerev ha'Machanehu" (in the camp - va'Yitosh Al ha'Machaneh 1 " (Bamidbar 11:31), and also "Saviv l'Mishkenosav" - "Sevivos ha'Machaneh" (ibid).
2.
Malbim: They were "b'Kerev ha'Machanehu Saviv l'Mishkenosav" (right near their tents), even though birds' nature is to distance from people.
1
Some say that "Al ha'Machaneh" is by (outside) the camp! Refer to Bamidbar 11:31:152:2, 11:32:3:2 and the notes there.
