Giving up Mahr already fixed by the villagers

Q: As a father, I have arranged for my son to be engaged to a girl. After she and her father accepted, we agreed upon the Mahr (dowry to a bride from the groom) and all the conditions of the marriage contract. After a period of time, our village and a neighboring one decided upon the Mahr and set its conditions with less than what I decided with my son's father-in-law. Indeed, my son proposed to his fiancée before setting this agreement and the people in the village want me to abide by the conditions of their agreement. However, I am taking care not to violate any of the conditions stipulated in the marriage contract lest it should be rendered invalid. Kindly give me your Fatwa in this regard. Should I abide by the terms of the marriage contract, or the agreement between the two villages, bearing in mind that (Part No. 19; Page No. 76) it stipulates that the waliy of the bride and the bridegroom should take an oath?

A: If the case is as you mentioned, the bridegroom should abide by the conditions of the marriage contract, for Allah (Glorified be He) states: O you who believe! Fulfil (your) obligations. The Prophet (peace be upon him) stated: The stipulations most entitled to be abided by are those with which you are given the right to enjoy the (women’s) private parts (i.e. the stipulations of marriage contract). May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.