God told Samuel he would judge Eli’s house for the iniquity Eli knew about, because his sons were blaspheming and he did not restrain them. The text says the iniquity of Eli’s house would not be atoned for by sacrifice or offering. 1 Samuel 3:11–14
In 1 Samuel 3:11–14, Yahweh tells Samuel that a shocking event is coming for Israel—so startling that people will react with dread. The message focuses on Eli’s family line: what God has already spoken about Eli’s “house” will now be carried out completely. The reason given is that Eli knew about his sons’ wrongdoing and did not stop it. This section sits inside Samuel’s first nighttime call, where the boy Samuel learns to recognize Yahweh’s voice and receives his first prophetic message (see the wider scene in 1 Samuel 3:1–21). The speech is not a general warning but a specific announcement about Eli’s family leadership at the sanctuary.
This speech introduces Samuel’s first prophetic message: Yahweh is about to act in a way that will be widely heard and deeply disturbing in Israel (verse 11). The focus is not a vague threat but the completion of earlier warnings against Eli’s “house” (his family line and its priestly leadership) (verse 12).
A careful answer keeps the immediate passage, the book's argument, and the whole-Bible storyline together, so the question is answered in context instead of as a detached idea.
Start with 1 Samuel 3:11-14, then read the surrounding section so the answer stays connected to the passage's flow.
11Yahweh said to Samuel, Behold, I will do a thing in Israel, at which both the ears of everyone who hears it shall tingle.
12In that day I will perform against Eli all that I have spoken concerning his house, from the beginning even to the end.
13For I have told him that I will judge his house forever, for the iniquity which he knew, because his sons did bring a curse on themselves, and he didn`t restrain them.
14Therefore I have sworn to the house of Eli, that the iniquity of Eli`s house shall not be expiated with sacrifice nor offering forever.