This man Samuel, seemed to have clout with God, so as to say, or that was what the Israelites were witnessing. He was claiming that a miracle would happen as a sign of their wrongdoing in asking for a king and it did happen. And the Bible says, "So all the people stood in awe of the Lord and of Samuel."
Samuel, the prophet, had lead Israel since he was a youth. He was faithful in all his ways towards God and towards his fellow Israelites. Now it was time for him to move away from his God given position as leader of Israel, because the people had asked for a king and he had selected one for them taking God's guidance. He challenged the people to witness against him regarding any wrongdoing on his part in all his service. They replied, "You have not cheated or oppressed us, you have not taken anything from anyone's hand." (1 Samuel 12:4)
There was thunder and rain during wheat harvest season when Samuel prayed to God.The people were afraid and said to Samuel, "Pray to the Lord your God for your servants so that we will not die, for we have added to all our other sins the evil of asking for a king." (1 Samuel 12:19)
"Do not be afraid," Samuel replied. "You have done all this evil; yet do not turn away from the Lord, but serve the Lord with all your heart. (1 Samuel 12:20)
The prophet Samuel lived very close to the Lord and served the Lord with all his heart. In his service for the Lord as prophet, judge and priest, he was faithful. From the beginning of his ministry to the end, the Lord was continually with him and the let none of his words fall to the ground.
May the Lord grant us grace to be faithful in our calling too.