1)
Why is "uch'Echav" missing the latter Aleph?
1.
Radak: Achav's name is abbreviated, for disgrace. Sometimes adding is for disgrace - "ha'Aminun Achicha" (Shmuel II, 13:20).
2)
What is the meaning of "Kalam"?
1.
Rashi (from Sanhedrin 93a): It is an expression of roasting through fire. Radak - he burned them.
