He said, “What is the thing that he has spoken to you? Please don’t hide it from me. God do so to you, and more also, if you hide anything from me of all the things that he spoke to you.” Samuel told him every bit, and hid nothing from him. He said, “It is Yahweh. Let him do what seems good to him.” 1 Samuel 3 (WEB)
Prophecy 101: How to listen to God, and how to deliver his message. Eli taught Samuel these important skills, even to hear a negative prophecy against his own family. Did Eli respond rightly? At first glance, it seems like he did, as he's submitting to God's will. But compare the response of the Ninevites: Jonah says God will destroy them, they repent, and God doesn't destroy them!
God wanted Eli to rebuke his blasphemous sons. God says this sin can't be forgiven by sacrifice or grain offering. Can any sin be forgiven by a grain offering? God demands obedience, only Christ's blood can cover sins (Heb 10, Psalm 40:6, 1 Samuel 15:22).
Do not wonder at this; for the time is coming when all who are in their graves will hear his voice, and will come out – those who have done good rising to life, and those who have lived evil lives rising for condemnation. I can do nothing of myself; I judge as I am taught; and the judgment that I give is just, because my aim is not to do my own will, but the will of him who sent me. John 5 (OEB)
Eli will rise for judgement by Christ. How did he respond when confronted by his sin? How do you respond when confronted with your sin? Do you deny it? Act like it's not real? Do you accept it? Act as if it's no big deal? Or do you repent and obey God?