What is the meaning of "Misnasei"?
Rashi: He glorified himself.
Why did he make himself king?
Radak: He was very beautiful - more than his brothers, and he thought that his father loved him, for he never rebuked him and he never angered him (refer to 1:6:1:2.
Radak (6): If Daniel (Avigayil's son; in Shmuel II, 3:3 he is called Kil'av) had already died 1 , Adoniyahu was David's oldest living son].
Malbim (2-3): It was because David's strength waned and he ceased to rule, and lied on a bed covered with garments. He was alone with Avishag; no one would enter to tell him that Adoniyahu seized power. Also, from when he saw Avishag he had a burning lust for her; he wanted to become king in order to take her.
Malbim (6): He had already died. (What is his source? Malbim himself (Divrei ha'Yamim I, 3:1) says that [later] Adoniyahu thought to rule, even though Kil'av was older, because people said that perhaps Kil'av was really the son of Naval (David married Avigayil shortly after Naval died), or because he always learned Torah and was not interested in being king! This requires investigation. - PF)
How did he "make" 50 men running in front of him?
Rashi, citing Sanhedrin 21b: He removed their spleens (Rashi 21b - through a potion, for the spleen weighs a person down) and the skin of the bottom of their feet [Rashi 21b - so they could run faster, and thorns would not hurt them 1 ].
Radak: (He armed them.) They went in front of him, like the custom for armed foot soldiers to go in front of the king. Also Avshalom did so (Shmuel II, 15:1).
Would it not suffice that they wore shoes?! Chashukei Chemed (21b) - Adoniyahu wanted to show his grandeur, that people can run in front of him without tiring, and [barefoot] on thorns. Yad Ramah (21b) - some say that they did not have a bone in their feet.
