1 Samuel 3:5-9

5He ran to Eli and said, “Here I am, for you called me.” But Eli said, “I did not call you; lie down again.” So he went and lay down.

6Then the Lord called yet again, “Samuel!” So Samuel got up and went to Eli and said, “Here I am, for you called me.” But Eli answered, “I did not call, my son; lie down again.”

7Now Samuel did not yet know [or personally experience] the Lord, and the word of the Lord was not yet revealed [directly] to him.

8So the Lord called Samuel a third time. And he stood and went to Eli and said, “Here I am, for you did call me.” Then Eli understood that it was the Lord [who was] calling the boy.

9So Eli said to Samuel, “Go, lie down, and it shall be that if He calls you, you shall say, ‘Speak, Lord, for Your servant is listening.’ ” So Samuel went and lay down in his place.