What is the ruling regarding someone who commits a grave sin and does not reveal it in this world, then repents from it and dies without restoring the rights to their owners or atoning for it?

An-Nawawi stipulated for repentance from sins related to the rights of others that one must seek absolution from the owner of the right, either by his forgiveness or by giving him his due. This is supported by the hadith in Al-Bukhari: "Whoever has wronged his brother concerning his honor or anything else, let him seek his forgiveness today before there will be no Dinar or Dirham." It is recommended for one who knows of this matter to have mercy on the deceased and ask the rightful claimants to forgive him, or to give them their due so that the deceased may be absolved.