Vowing not to commit a sin and breaching the vow

Q 2: a man promised Allah (Exalted be He) that he would not do any Munkar (that which is unacceptable or disapproved of by Islamic law and Muslims of sound intellect); he fulfilled his promise for three months but then he broke it. What is the ruling on this? Does this man have to make any Kaffarah (expiation)? Can his Tawbah (repentance to Allah) be accepted?

A: If the reality is exactly as what is mentioned in the question that this man promised Allah (Exalted be He) not to commit a Munkar then he did so; committing a Munkar is considered a sin and not fulfilling the concerned promise is another one. Thus, the person in question has to make Tawbah (repentance to Allah) and Istighfar (seeking forgiveness from Allah). He has to follow his bad deeds by good ones. He has to perform the congregational Salah regularly, recite the Qur'an, give Sadaqah (voluntary charity) and keep the ties of kinship so that hopefully Allah (Exalted be He) will accept his Tawbah and forgive his sins. The person in question is not required to make any Kaffarah but he should not return to the same sin again.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.