1 Samuel 3:8-9
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.
10Then God came and stood before him exactly as before, calling out, "Samuel! Samuel!"
Samuel answered, "Speak. I'm your servant, ready to listen."