The boy Samuel served the LORD under the direction of Eli. In those days the LORD didn't give many messages to his people. He didn't give them many visions.
References for 1 Samuel 3:1
One night Eli was lying down in his usual place. His eyes were becoming so weak he couldn't see very well.
Samuel was lying down in the LORD's house. That's where the ark of God was kept. The lamp of God was still burning.
The LORD called out to Samuel. Samuel answered, "Here I am."
He ran over to Eli. He said, "Here I am. You called out to me." But Eli said, "I didn't call you. Go back and lie down." So he went and lay down.
Again the LORD called out, "Samuel!" Samuel got up and went to Eli. He said, "Here I am. You called out to me." "My son," Eli said, "I didn't call you. Go back and lie down."
Samuel didn't know the LORD yet. That's because the LORD still hadn't given him a message.
The LORD called out to Samuel for the third time. Samuel got up and went to Eli. He said, "Here I am. You called out to me." Then Eli realized that the LORD was calling the boy.
So Eli told Samuel, "Go and lie down. If someone calls out to you again, say, 'Speak, Lord. I'm listening.' " So Samuel went and lay down in his place.
The LORD came and stood there. He called out, just as he had done the other times. He said, "Samuel! Samuel!" Then Samuel replied, "Speak. I'm listening."
The LORD said to Samuel, "Pay attention! I am about to do something terrible in Israel. It will make the ears of everyone who hears about it ring.
"At that time I will do everything to Eli and his family that I said I would. I will finish what I have started.
I told Eli I would punish his family forever. He knew his sons were sinning. He knew they were making fun of me. In spite of that, he failed to stop them.
"So I took an oath and made a promise to the family of Eli. I said, 'The sins of Eli's family will never be paid for by bringing sacrifices or offerings.' "
Samuel lay down until morning. Then he opened the doors of the LORD's house. He was afraid to tell Eli about the vision he had received.
But Eli called out to him. He said, "Samuel, my son." Samuel answered, "Here I am."
"What did the LORD say to you?" Eli asked. "Don't hide from me anything he told you. If you do, may God punish you greatly."
So Samuel told him everything. He didn't hide anything from him. Then Eli said, "He is the Lord. Let him do what he thinks is best."
As Samuel grew up, the LORD was with him. He made everything Samuel said come true.
So all of the people of Israel recognized that Samuel really was a prophet of the Lord. Everyone from Dan all the way to Beersheba knew it.
The LORD continued to appear at Shiloh. There he made himself known to Samuel through the messages he gave him.