What was the Ru'ach Hashem?
Radak citing Targum Yonasan: It was a spirit of strength, from Hashem.
What is the meaning of "va'Yshas'ehu"?
Radak citing Targum Yonasan: It is cutting something into two. In Vayikra 1:17, since it said "v'Shisa Oso vi'Chnafav", it needed to say "v'Lo Yavdil" (for v'Shisa implies that he divides it into two).
Why does it say "k'Shasa ha'Gedi"?
Malbim: It shows double strength. (a) He divided it easily like a kid, the smallest domestic animal 1 . (b) He did so with his bare hands - "u'Me'umah Ein b'Yado."
Malbim: Rashi (Shemos 23:19, regarding "Lo Sevashel Gedi", says that a tender nursing animal is called Gedi.
Why didn't he tell his parents?
Malbim: He understood that Hashem brought this about so he 1 would know that he is prepared to succeed against Hashem's enemies, like David said "Gam Es ha'Ari Gam ha'Dov" (Shmuel 1:17:36).
Presumably, Malbim means that since it happened when he was alone, he understood that Hashem did not want his parents to know.
