1 Samuel 3:1-10 KJV
And the child Samuel ministered unto the LORD before Eli. And the word of the LORD was precious in those days; there was no open vision. And it came to pass at that time, when Eli was laid down in his place, and his eyes began to wax dim, that he could not see; 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. 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. 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.