1 Samuel 3:14

I have taken an oath concerning Eli's family line. No offering or sacrifice will ever be able to make peace for the sins that Eli's family committed.

Isaiah 22:14

Jehovah of Hosts has disclosed himself in my ears: Surely this iniquity will not be forgiven you until you die, says Jehovah of Hosts.

1 Samuel 2:25

If one man sins against another, God will judge him. But if a man sins against Jehovah, who will intercede for him? But his sons did not listen to the voice of their father. Jehovah desired to put them to death.

Leviticus 15:31

You must separate the Israelites from anything that keeps them from being presentable to me. Otherwise they will die. This is because they defile my tent, which is among them, and make it unclean.

Numbers 15:30-31

Any who sin deliberately, natives or foreigners, are guilty of treating Jehovah with contempt. They shall be put to death.

Psalm 51:16

You do not desire sacrifice. Otherwise, I would offer one to you. You are not pleased with burnt offerings.

Jeremiah 7:16

As for you, do not pray for this people. Do not lift up cry or prayer for them, and do not intercede with me for I do not hear you.

Jeremiah 15:1

Jehovah said to me: I would not feel sorry for these people, even if Moses and Samuel were standing in front of me. Send them away from my presence, and let them go.

Ezekiel 24:13

In your filthiness is lewdness. Because I would have cleansed you, yet you are not clean. You will not be cleansed from your filthiness again until I have spent my anger on you.

Hebrews 10:4-10

It is not possible for the blood of bulls and of goats to take away sins.

Hebrews 10:26-31

If we continue to (practice) (deliberately persist in) sin willfully after we have received the knowledge of the truth, there remains no more sacrifice for sins.

Treasury of Scripture Knowledge

Summary

And therefore I have sworn unto the house of Eli, that the iniquity of Eli's house shall not be purged with sacrifice nor offering for ever.

Bible References

The iniquity

1 Samuel 2:25
If one man sins against another, God will judge him. But if a man sins against Jehovah, who will intercede for him? But his sons did not listen to the voice of their father. Jehovah desired to put them to death.
Numbers 15:30
Any who sin deliberately, natives or foreigners, are guilty of treating Jehovah with contempt. They shall be put to death.
Psalm 51:16
You do not desire sacrifice. Otherwise, I would offer one to you. You are not pleased with burnt offerings.
Isaiah 22:14
Jehovah of Hosts has disclosed himself in my ears: Surely this iniquity will not be forgiven you until you die, says Jehovah of Hosts.
Jeremiah 7:16
As for you, do not pray for this people. Do not lift up cry or prayer for them, and do not intercede with me for I do not hear you.
Jeremiah 15:1
Jehovah said to me: I would not feel sorry for these people, even if Moses and Samuel were standing in front of me. Send them away from my presence, and let them go.
Ezekiel 24:13
In your filthiness is lewdness. Because I would have cleansed you, yet you are not clean. You will not be cleansed from your filthiness again until I have spent my anger on you.
Hebrews 10:4
It is not possible for the blood of bulls and of goats to take away sins.