Is there any authentic hadith that says “the sin committed against the right of a person is far greater than a sin committed against Allah swt?” it further said that sin committed against Allah might be forgive but the sin against one of his slaves will not be forgiven unless the person forgives himself. please tell me if there is anything closely related to this.
I don’t know of any such hadeeth! There are rights of others that Allah doesn’t forgive as the others must take from your good deeds on the day of judgement. But also there are rights of Allah that are greater and Allah will never forgive if a person dies while committing such as shirk.