The Lord was with Samuel as he grew up, and he let none of Samuel’s words fall to the ground

1 Samuel  3:11-21

At that time I will carry out against Eli everything I spoke against his family—from beginning to end. For I told him that I would judge his family forever because of the sin he knew about; his sons blasphemed God, and he failed to restrain them. Therefore I swore to the house of Eli, ‘The guilt of Eli’s house will never be atoned for by sacrifice or offering.’”

So Samuel told him everything, hiding nothing from him. Then Eli said, “He is the Lord; let him do what is good in his eyes.”

The Lord was with Samuel as he grew up, and he let none of Samuel’s words fall to the ground. And all Israel from Dan to Beersheba recognized that Samuel was attested as a prophet of the Lord. The Lord continued to appear at Shiloh, and there he revealed himself to Samuel through his word.

Why?

Blessing is Samuel who could be a servant of the Lord, and Samuel knows how to follow the word of the Lord. None of Samuel's words fall to the ground, Samuel says what told him. And Samuel has a similar power from the Lord.

Eli knew the consequence of his sons blasphemed God and he failed to restrain his sons. So the house of Eli's will never be atoned for by the sacrifice of offering. The family of Eli won't be servants of the Lord anymore.

The Lord is sovereign over the whole universal, so Eli said let him do what is good in his eyes. This is the truth, but the Lord has mercy and righteousness, unlike human beings.

How?

God is good and righteous, any one against the Lord will be judged by the Lord. People maybe don't know, but the Lord knows everything.