1 Samuel 3:6-7
6-7God called again, "Samuel, Samuel!"
Samuel got up and went to Eli, "I heard you call. Here I am."
Again Eli said, "Son, I didn't call you. Go back to bed." (This all happened before Samuel knew God for himself. It was before the revelation of God had been given to him personally.)
8-9God called again, "Samuel!"—the third time! Yet again Samuel got up and went to Eli, "Yes? I heard you call me. Here I am."
That's when it dawned on Eli that God was calling the boy. So Eli directed Samuel, "Go back and lie down. If the voice calls again, say, 'Speak, God. I'm your servant, ready to listen.'" Samuel returned to his bed.