Now Samuel didn't yet know Yahweh, neither was the word of Yahweh yet revealed to him.
it can only be understood, that he had not learnt it perfectly; somewhat he knew of it, but in an imperfect manner, being a child: but the sense of the word is, that as yet he was ignorant that God had used to speak with ordinary and familiar voice to men, as Maimonides says s; he perhaps had never heard of any such thing, and much less was experimentally acquainted with it, that God ever did speak after such a manner to men, and could not distinguish between the voice of God and the voice of Eli: