What is the ruling regarding the financial obligations (nafaqa) of a Mukatab (a slave contracted for manumission)?

Primary text

The financial obligations of a Mukatab concerning the maintenance of wives, children, and relatives follow the ruling of a fully enslaved person, as long as he still owes part of his redemption price. However, if the Mukatab has a wife, he must provide her maintenance from his earnings. This is because the maintenance of the wife is obligatory based on the principle of exchange (mu'awada), irrespective of wealth or poverty, just as it is obligatory upon a full slave, making it more incumbent upon the Mukatab. Furthermore, the wife's maintenance cannot be waived unless she provides something that waives it, and it cannot be imposed upon the master, because the Mukatab's maintenance is not due from the master, making his wife's maintenance the primary obligation upon him.