1)
What is the meaning of "Ad Hismahmam"?
1.
Rashi: It is while they were delaying.
2.
Malbim: He already fled in the proper time to delay. He did not expect them to wait longer (refer to 2:25:1:2).
2)
What is the meaning of "ha'Se'irasah"?
1.
Rashi: It is a thin and thick 1 forest. It is a good place to hide. We find that branches of thin trees are called Sa'ar (Kil'ayim 4:9, Pe'ah 2:3).
2.
Radak: It is the name of a place.
1
Perhaps this means that in some places it is thick, and in other places it is thin. Or, the trees are thin, but they are spaced thickly (close to each other), or vice-versa. However, seemingly a totally thick forest is better for hiding! (PF)
