The child Samuel ministered to Yahweh before Eli. The word of Yahweh was precious in those days; there was no frequent vision.
The writer may have intended to mark the beginning of Samuel’s ministry with his statement that the lad opened the doors (i.e., the curtained openings into the courtyard) of the Lord’s house (1 Samuel 3:15; cf. 1 Samuel 1:28 b). [Note: See J. Gerald Janzen, "’Samuel Opened the Doors of the House of Yahweh’ (1 Samuel 3:15)," Journal for the Study of the Old Testament 26 (June 1983):89-96.] Evidently the curtained openings were closed at night.