What is the meaning of "what your right hands possess," and what is the expiation for freeing a slave, upon whom is it obligatory, and how is it performed?

Expiation (kaffarah) by manumission is obligatory in a specific order for Dhihar (injurious assimilation) and unintentional killing, by consensus. For fasting, this is the preferred view. As for the expiation for an oath, one has the choice between feeding and manumission, and fasting is only permissible if one is unable to do either. The slave (raqabah) that is acceptable for expiation must be a Muslim and free from defects. Scholars have differed regarding the condition of faith (Islam) for the manumitted slave; some have interpreted the general (unrestricted) texts as being restricted by the specific (restricted) texts.