1 Samuel 3:1-10 (ESV)
Now the boy Samuel was ministering to the Lord in the presence of Eli. And the word of the Lord was rare in those days; there was no frequent vision.
2 At that time Eli, whose eyesight had begun to grow dim so that he could not see, was lying down in his own place. 3 The lamp of God had not yet gone out, and Samuel was lying down in the temple of the Lord, where the ark of God was.
4 Then the Lord called Samuel, and he said, “Here I am!” 5 and ran to Eli and said, “Here I am, for you called me.” But he said, “I did not call; lie down again.” So he went and lay down.
6 And the Lord called again, “Samuel!” and Samuel arose and went to Eli and said, “Here I am, for you called me.” But he said, “I did not call, my son; lie down again.” 7 Now Samuel did not yet know the Lord, and the word of the Lord had not yet been revealed to him.
8 And the Lord called Samuel again the third time. And he arose and went to Eli and said, “Here I am, for you called me.” Then Eli perceived that the Lord was calling the boy. 9 Therefore Eli said to Samuel, “Go, lie down, and if he calls you, you shall say, ‘Speak, Lord, for your servant hears.’ ” So Samuel went and lay down in his place.
10 And the Lord came and stood, calling as at other times, “Samuel! Samuel!” And Samuel said, “Speak, for your servant hears.”