1 Samuel 3:6-9

6And Jehovah called yet again, Samuel. And Samuel arose and went to Eli, and said, Here am I; for thou calledst me. And he answered, I called not, my son; lie down again. 7Now Samuel did not yet know Jehovah, neither was the word of Jehovah yet revealed unto him. 8And Jehovah called Samuel again the third time. And he arose and went to Eli, and said, Here am I; for thou calledst me. And Eli perceived that Jehovah had called the child. 9Therefore Eli said unto Samuel, Go, lie down: and it shall be, if he call thee, that thou shalt say, Speak, Jehovah; for thy servant heareth. So Samuel went and lay down in his place.