The child Samuel ministered to Yahweh before Eli. The word of Yahweh was precious in those days; there was no frequent vision.
The point made here is important.  Up until this time in Israel a prophet had not always been available to instruct the people in matters divine.  "The prophecy of Hannah, and that of the man of God  (1 Samuel 2:27ff, above), are the only instances of prophecy since Deborah."[9] Samuel is mentioned in  Acts 3:24 as the first of the prophets after Moses. The importance of this lies in the fact that God's promise to raise up a prophet like unto Moses  (Deuteronomy 18:15) should not be understood as a promise to raise up "a continual line or succession of prophets," as some have vainly supposed, but it is a direct and specific prophecy of the Messiah.