What is the ruling on one who swore an oath while reconciling between two parties, and then broke it?

Swearing with the intention of reconciliation, such as saying, "By Allah, I will do such and such," or "By Allah, so-and-so said such-and-such about you," for the purpose of mending relations, is permissible as long as it does not harm anyone. As for a promise, fulfilling it is one of the characteristics of believers, while breaking it is a trait of hypocrites, as Allah says concerning Ismail: (Indeed, he was truthful in [his] promise, and he was a messenger and a prophet) Maryam/54. If one swears to a promise and does not fulfill it, he must offer expiation for a broken oath, and he would have adopted a characteristic of the hypocrites. The apparent legal evidence confirms that fulfilling a promise is obligatory and breaking it is forbidden. Lying is permissible in reconciling people if it does not harm anyone, but rather benefits the group, as the Prophet, peace and blessings be upon him, said: (He is not a liar who reconciles between people by conveying good or saying good).