It is narrated from Sayyiduna Abu Hurayrah (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "When one of you obstinately holds to an oath sworn concerning his family (even though breaking the oath would be better), this deed of his is more sinful in the sight of Allah than paying the expiation he has been commanded to give." This hadith is sahih (authentic) on the condition of the two Shaykhs (Bukhari and Muslim), but they did not record it.