How are maintenance and earnings divided if the partially freed slave and the master agree upon 'Al-Muhaya'ah' (alternation of days)?

Primary text

If the master and the partially freed slave agree to the arrangement of Al-Muhaya'ah, the slave's earnings and maintenance during the days allocated to the slave belong to the slave. Conversely, during the days allocated to the master, the slave's earnings belong to the master, and the maintenance falls upon the master.