What is the meaning of "Hish'iltihu la'Shem"?
Rashi: This is like one who lends a Kli to his Rebbi, or lends his son to serve [his Rebbi].
Radak: I returned to Him the loan that He gave to me.
Radak citing Targum Yonasan: I gave him over to serve Hashem.
Why did she say "Chayah" (past tense)? She should have said Yichyeh (future)!
Radak: We often find like this (past in place of future).
Why did she say that he is "Sha'ul" to Hashem?
Rashi: Since I lent him to Hashem, you are not authorized to punish him.
Radak: He is given to Hashem.
Radak citing Midrash Shmuel 3:6: She said with Ru'ach ha'Kodesh, that as long as Shmuel lives, Sha'ul will live.
Who bowed to Hashem?
Rashi #1: Shmuel bowed. Radak -even though he was only two, they taught him to bow to Hashem.
Rashi #2: Elkanah bowed.