1)
What is the message here?
1.
Malbim: Surely, it is not proper that one who murders his father's house should inherit his honor. Therefore, your end will be like [the parable of] the trees from the Atad - fire will go out...
2)
What is "Beis Melo"?
1.
Radak: It is the name of a place, and not an adjective. Also (Yehoshua 24:!4) "v'Ivdu Oso b'Samim uve'Emes" [are nouns, and not adverbs].
