Permissibility of freeing a slave after killing someone by mistake whose guardians refuse to retaliate or take Diyah

Q: I accidentally killed one of my tribe members. This happened during our celebration on the Day of `Eid. His heirs relinquished their right of Qisas (just retaliation) and Diyah (blood money) and forgave me without any terms or conditions because of the friendship between us. My question now is:Is it possible to free a bondsman, and could you arrange make this option available? I should mention that I do not have all the money I need to free a bondsman at this time, but I will receive the funds after I leave prison from the benefits of my previous job.Should I fast two consecutive months instead to fulfill my obligation?Please advise. May Allah guide you and may Allah's Peace, Mercy, and Blessings be with you!

A: If the matter is as mentioned, you must pay the Kaffarah (expiation) of involuntary manslaughter (Part No. 21; Page No. 426) because you have killed a person of your tribe. The Kaffarah is to free a Muslim bondsman whether you have the money now or will have it in the future. If you are unable to do this, you must fast for two consecutive months.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.