What is the ruling on the maintenance of a Mukatab's children born from his own female slave?

Primary text

The maintenance of the Mukatab's children born from his own female slave falls upon him because his offspring from his slave follows him; they become enslaved upon his enslavement and freed upon his manumission, making them equivalent to himself in terms of maintenance liability. Just as the Mukatab maintains himself, he maintains such a child. Furthermore, this child has no one to maintain him other than his father, as the mother is a slave belonging to the Mukatab, and he has no free relatives to assume the duty, thus it falls upon the Mukatab, similar to his mother. There is no harm to the master in the Mukatab maintaining his child from his slave: if the Mukatab pays his redemption price and becomes free, he has fulfilled the writing obligation, and the master has no further claim; if he defaults and becomes enslaved again, the Mukatab and his child whom he maintained return to him, making it as if he spent on his own slave, and this maintenance becomes like his expenditure on all his other slaves.