Sayyiduna Jawdan (may Allah be pleased with him) said: the Messenger of Allah (peace and blessings be upon him) said: "Whoever offers an apology to his brother and he does not accept his apology, upon him is a sin like the sin of a tax collector."
Hadith Referenceالمعجم الكبير للطبراني / باب الجيم / 2143