Why did Chanah not ascend to the Mishkan to bring her Korban Yoledes? L'Chatchilah, she herself should give it to the Kohen!
Malbim: She thought that her vow included that once she brings him, he will remain there his entire life. 1
She thought that Shmuel is weak and he could get sick if he goes to Shilo before two years (Chagigah 6a), so she could not take him with her. She could not go without him, for a baby is prone to refuse to nurse from anyone other than his mother (Kesuvos 59b). (PF)
Indeed, she brought the Korban at the earliest possible time (41 days after birth), which is l'Chatchilah. If she could not go herself, she sent it via Elkanah or a Shali'ach. (PF)
I.e. due to her vow, she could not bring her Korban herself. She sent it with Elkanah. Or, perhaps she did not want to wait until the coming Regel, and sent it with a Shali'ach immediately after the 40 days of Tum'as Yoledes and Yemei Tohar. Surely her vow would not allow her to delay almost two years before bringing it, and transgress Bal Te'acher! - PF]
When would she wean him?
Rashi citing Kesuvos 60a: It is after 24 months.
How could she delay bringing him? A father must bring his son to the Mikdash on each Regel once he can ride on his father's shoulder or walk holding his father's hand (Chagigah 2a)!
Radak citing Chagigah 6a: Shmuel was pampered and weak. Chanah feared lest he fall sick due to the journey.
What is the significance of "va'Yashav Sham Ad Olam"?
Rashi (from Ta'anis 5b): "Olam" for Leviyim is 50 years - "umi'Ven Chamishinm Shanah
Even though the pregnancy was just over six months, the seven months that the Aron was in Sedei Pelishtim compensate for the difference. It is reasonable that the years of Eli's and David's reign, and the years that the Aron was in Kiryas Ye'arim, are not precise from month to month. (PF)
