Here am I

[1 Sam. 3:1] And the child Samuel ministered unto the LORD before Eli. And the word of the LORD was precious in those days; there was no open vision.
Josephus says that Samuel had just completed his twelfth year, his ministry consisted, of course, of such duties in or about the sanctuary as were suited to his age. Whether the office had been specially assigned him, or it arose from the interest inspired by the story of his birth, Eli kept him as his immediate attendant; and he resided not in the Sanctuary, but in one of the tents or apartments around it, assigned for the accommodation of the priests and Levites, his being near to that of the high priest.
Word precious in those days was very rarely known to the Israelites; and in point of fact only two prophets are mentioned as having appeared during the whole administration of the judges (Judges 4:4, 6:8).
No open vision, no publicly recognized prophet whom the people could consult, and from whom they might learn the will of G-d. There must have been certain undoubted evidences by which a communication from heaven could be distinguished. Eli knew them, for he may have received them, though not as frequently as is implied in the idea of an "vision open."
The lamp of G-d had not yet gone out means it was the morning hours, but it was still dark and therefore the lamp had not yet been put out. The "Temple" seems to have become the established designation of the Tabernacle, and the time indicated was towards the morning twilight, as the lamps were extinguished at sunrise (Leviticus 6:12, 13).
The fact that Samuel could not identify the source of the voice points to the fact that there was nothing visual; he could only hear the voice. Samuel had heard the voice very clearly but instead of running to G-d he ran to Eli. Eli the priest was perhaps convinced that G-d would speak only through him. He was the one to receive any oracle from G-d and to communicate it to the people. He could not at first believe that G-d could also reveal his will to other people. Therefore, he rejected Samuel’s claim to have heard a call and tried to silence him and make him sleep. It took Eli some time (three is a symbolic number indicating fullness) before he realized that it could be that Yahweh was calling Samuel. Only then did he give proper instructions to Samuel as to how he should receive the call.
It is evident that his sleeping chamber was close to that of the aged high priest and that he was accustomed to be called during the night. The three successive calls addressed to the boy convinced Eli of the divine character of the speaker, and he therefore exhorted the child to give a respectful attention to the message. The burden of the L-rd's message was an extraordinary forewarning of the judgments that impended over Eli's house; and the aged priest, having drawn the painful secret from the child, exclaimed, "It is the L-rd; let him do what seemeth him good." Such is the spirit of meek and unmurmuring submission in which we ought to receive the dispensations of G-d, however severe and afflictive. But, in order to form a right estimate of Eli's language and conduct on this occasion, we must consider the overwhelming buildup of judgments denounced against his person, his sons, his descendants - his altar, and nation. With such a threatening prospect before him, his piety and meekness were wonderful. In his personal character he seems to have been a good man, but his sons' conduct was openly bad; and though his misfortunes claim our sympathy, it is impossible to approve or defend the weak and unfaithful course which, in the retreated justice of G-d, brought these adversities upon him.
Yahweh says to Samuel, ‘on that day I will fulfill against Eli all that I have spoken concerning his house, from beginning to end’. But according to 2:30, Yahweh has earlier promised to Eli, your house and the house of your father should go in and out before me forever.’ This promise of G-d is no longer honored; the house of Eli is now to be removed. The word of the L-rd is the medium of the communication of the will of G-d. The context of the word has now changed, and so also has the need for the will of G-d to be communicated differently. What came earlier to Eli as an oracle of salvation comes to him now as an oracle of doom. It does not change the content of the Word of G-d, namely, the ultimate purpose of G-d.
The word may be influenced and changed by its context. Thus Eli was only an instrument in the hand of G-d towards the fulfillment of the ultimate purpose of the salvation of his people; it had itself, become a hindrance to the people. Samuel was called to do something new in Israel, something different from what the house of Eli has done. Removal of oppressive structures precedes the creation of liberative structures.
Eli symbolizes institutional religion. The judgment against Eli is not a judgment against an individual person or family, by against a structure. It is against the priestly religion as a whole, which had failed in guiding people to G-d. The task of the priesthood is to guide people to G-d and to help them to abide in an active relation to G-d, and to handle matters according to His will. In this task Eli and his priestly religion had failed. Instead of leading people to G-d, they were leading the people to themselves, to listen to their own words and to act accordingly.
Eli is anxious to know what G-d told Samuel, and Samuel shares everything with him. Eli accepts G-d’s will and submits himself to it. With that Eli’s role comes to an end, though we do meet him again in 4:12-18.
The account of Samuel’s ministry begins. All people from Dan to Beer-sheba (from the whole land, from north to south) came to know him as a prophet. It is important that people who speak in the name of G-d first receive that word from G-d.