1 Samuel 3:3–10
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.