1 Samuel 3:5-9

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

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

7(Now Samuel did not yet know the Lord, nor was the word of the Lord yet revealed to him.)

8And the Lord called Samuel again the third time. So he arose and went to Eli, and said, “Here I am, for you did call me.” Then Eli perceived that the Lord had called the boy.

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