Sayyiduna Abu Hurairah (may Allah be pleased with him) narrates that the Messenger of Allah (peace and blessings be upon him) said: There are five evils for which nothing can serve as atonement: associating partners with Allah, killing someone without right, robbing a believer, fleeing on the day of battle, and a false oath through which wealth is usurped without right.
Hadith Referenceالفتح الربانی / كتاب آفات اللسان / 10007