1 Samuel 3:3-10

and the lamp of God had not yet gone out, and Samuel was lying down in the temple of the LORD where the ark of God was, that the LORD called Samuel; and he said, “Here I am.” Then he ran to Eli and said, “Here I am, for you called me.” But he said, “I did not call, lie down again.” So he went and lay down. The LORD called yet again, “Samuel!” So Samuel arose and went to Eli and said, “Here I am, for you called me.” But he answered, “I did not call, my son, lie down again.” Now Samuel did not yet know the LORD, nor had the word of the LORD yet been revealed to him. So the LORD called Samuel again for the third time. And he arose and went to Eli and said, “Here I am, for you called me.” Then Eli discerned that the LORD was calling the boy. And Eli said to Samuel, “Go lie down, and it shall be if He calls you, that you shall say, ‘Speak, LORD, for Your servant is listening.’ ” So Samuel went and lay down in his place. Then the LORD came and stood and called as at other times, “Samuel! Samuel!” And Samuel said, “Speak, for Your servant is listening.”