1)
Where was the Mizbe'ach?
1.
Rashi: It was in Giv'on.
2.
Radak: It was in Yerushalayim. Bamos were permitted then.
2)
Why did Adoniyahu grab onto the corners of the Mizbe'ach?
1.
Rashi citing Tanchuma Mas'ei 12: If Beis Din kills me, I will be buried in the cemetery of [people executed via] Beis Din. I would rather die here, and be buried in the gravesite of my ancestors.
