وفي الرقاب: يعان المكاتبون في فك رقابهم
Translation: Under “those in bondage,” contracted slaves are assisted to secure their freedom.
A mukātab, in the historical legal context, was an enslaved person with a contractual path to freedom through payment. This category supports the person in fulfilling that obligation.
The later prohibition on buying and freeing an enslaved person directly is not the same transaction as giving assistance to an eligible mukātab.