Swearing if he has a daughter to give her in marriage for no Mahr

Q: A person swore that if his wife gave birth to a girl, he would give her in marriage without Mahr (mandatory gift to a bride from her groom). Now, he has a daughter in the age of marriage and she is engaged. What should he do,as it has come to his knowledge that the Mahr is the bride's right, not his?

A: If the reality is as mentioned, he must offer Kaffarah (expiation) for an oath. The Kaffarah is to feed ten Miskins (needy persons) by giving each of them one and half kilograms of the staple food, or to clothe them by giving each one a Qamis (long shirt) or an Izar (garment worn below the waist) and a Rida' (garment worn around the upper part of the body), or to emancipate a believing slave. If none of these is affordable, he must observe Sawm (Fast) for three days.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.