Albert Barnes Commentary 1 Samuel 3:14

"And therefore I have sworn unto the house of Eli, that the iniquity of Eli`s house shall not be expiated with sacrifice nor offering for ever." — 1 Samuel 3:14 (ASV)

See the marginal references. The sin of the sons of Eli could not be purged by the appointed sacrifices of the Law. In blessed contrast with this declaration is the assurance of the New Testament (1 John 1:7; Acts 13:39).