1)
Why will David wipe out Naval and his house?
1.
Malbim: Naval disgraced David and his messengers
2)
Why did he say "Ben Beliya'al mi'Daber Elav"?
1.
Rashi: If I would speak to Naval about this, he would get angry at us.
2.
Radak: David is Ben Beliya'al. He will not speak to Naval, rather, he will wipe out [all of us] with his troops.
3.
Malbim: Naval calls David a Ben Beliya'al who casts off the yoke and rebels - "Rabu Avadim ha'Mispartzim" (verse 10).
