What is "ha'Machtesh"?
Rashi: It is the cavity [in the jawbone] in which a tooth rests. It is shaped like a Machteshes (mortar).
Radak based on Targum Yonasan: There was a rock under the jawbone. The stone was shaped like a Machteshes (mortar), therefore it is called Machtesh.
Malbim: It is a place in the form of a Machtesh (mortar). 1
It seems that he understands "ba'Lechi" to means in the place called Lechi, and not 'in (or under) the jawbone.' (PF)
Why was it called "Ein ha'Korei"?
Rashi: It is a Mayan (spring) that came about through the cry of [Shimshon,] who was Korei (called) to Hashem.
Malbim: They made a name to remember the miracle, for some say that one who sees the place must bless. All agree that the one for whom the miracle was done, he must bless. Initially the place was called Lechi due to the miracle of the jawbone. When another miracle was done, they added the name Ein ha'Korei, to bless on both of them (like the episode in Brachos 54a).
QUESTIONS ON RASHI
Rashi writes that water came out from the donkey's jawbone. Why did Shimshon need something Tamei to save his life?
