Radak: This is like El Hashem. We find like this - "v'Nasan ha'Sefer Al Asher Lo Yada" (Yeshayah 29:12). It is like El Lo Yada. "Al Shafan" (Melachim 2 22:8) is like El Shafan.

Malbim: Before, the Azarah was full, and she could not be alone to pour out her heart to Hashem. Now the Azarah was empty, and Eli sat for there were no Korbanos to offer now.

Malbim: Before, she relied on the prayer of her husband, who was a Tzadik. Now that she saw that he despaired [of having children from her], she prayed for herself.