1 Samuel 3:8 (KJV)

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;

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

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.

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.

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

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.

And the LORD came, and stood, and called as at other times, Samuel, Samuel. Then Samuel answered, Speak; for thy servant heareth.

And the LORD said to Samuel, Behold, I will do a thing in Israel, at which both the ears of every one that heareth it shall tingle.

In that day I will perform against Eli all things which I have spoken concerning his house: when I begin, I will also make an end.

For I have told him that I will judge his house for ever for the iniquity which he knoweth; because his sons made themselves vile, and he restrained them not.