What is the meaning of "va'Yasiru"?
Rashi citing Targum Yonasan: They sent others to spy it.
Why does it use an expression of Lasur, and not of Leragel?
Malbim: A Meragel goes to see Ervas ha'Aretz, i.e. the weakest parts that are easiest to capture. A Tar seeks the good; they were looking for a good place for the Machaneh to camp. They planned to besiege Beis Kel for many days.
Why does it say "va'Yasiru? b'Veis Kel"? Always, it says "Es" [the place spied]!
Malbim: They did not spy Beis Kel itself, rather, in [the outskirts of] Beis Kel.
Why does it mention the previous name of the city?
Radak citing Bereishis Rabah 69:8: Just like a Luz 1 has no mouth (opening), so no one could tell where is the opening to the city.
Malbim: It is so we will know that this is not Beis Kel near Ai, which was in Binyamin.
This is a nut or almond. Refer to Bereishis 30:37:152:1,2 and the note there.