1st Samuel 3:6

3 And ere the lamp of God went out in the temple of the LORD, where the ark of God was, and Samuel was laid down to sleep;

4 That the LORD called Samuel: and he answered, Here am I.

5 And he ran unto Eli, and said, Here am I; for thou calledst me. And he said, I called not; lie down again. And he went and lay down.

6 And the LORD called yet again, Samuel. And Samuel arose and went to Eli, and said, Here am I; for thou didst call me. And he answered, I called not, my son; lie down again.

7 Now Samuel did not yet know the LORD, neither was the word of the LORD yet revealed unto him.

8 And the LORD called Samuel again the third time. And he arose and went to Eli, and said, Here am I; for thou didst call me. And Eli perceived that the LORD had called the child.

9 Therefore Eli said unto Samuel, Go, lie down: and it shall be, if he call thee, that thou shalt say, Speak, LORD; for thy servant heareth. So Samuel went and lay down in his place.