May a Mukatab (a slave under contract for manumission) perform Hajj using money he has saved, provided the due date for his payment has not arrived?

Primary text

The explicit permission granted to a Mukatab to perform Hajj from saved funds before the due date of his required payment is predicated upon obtaining the permission of his master. Without the master's authorization, it is not permissible because it constitutes a voluntary transfer of funds for which he is obligated to spend, analogous to manumission.