Charles Spurgeon Commentary 1 Samuel 3:8-9

"And Jehovah called Samuel again the third time. And he arose and went to Eli, and said, Here am I; for thou calledst me. And Eli perceived that Jehovah 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, Jehovah; for thy servant heareth. So Samuel went and lay down in his place." — 1 Samuel 3:8-9 (ASV)

And he arose and went to Eli, and said, Here am I; for you called me. And Eli perceived that the LORD had called the child.

Therefore Eli said to Samuel, Go, lie down: and it shall be, if he calls you, that you shall say, Speak, LORD; for your servant hears.

So Samuel went and lay down in his place.

It was a chastisement to Eli that God did not speak directly to him, but sent him a message by another; and it must have been very humiliating to the aged man of God that God should select a little child to be his messenger to him.

Yet, as Eli had not been faithful, it was great mercy on God's part to speak to him at all; and no doubt the old man did not resent the fact that God, instead of speaking to one of his sons, or to himself, spoke by this little child.

Eli loved Samuel, and finding that the Lord intended to use this child, he did not grow jealous and angry, and begin to dampen the child's spirit; but he gave him wise directions how to act in case God should speak to him again.