Is it permissible for a son to take from his father's Zakat al-mal to help with his marriage, given that his father is in debt?

It is permissible for a father to pay zakat to his son who wishes to marry but does not have sufficient means, or to pay off his son's debt, provided the debt is not for expenses obligatory upon the father. However, it is not permissible for a father to pay his zakat to his poor son, because the son's maintenance is obligatory upon him. If it is permissible to pay zakat to the son, the father must hand over the money to him, and then the son must pay off his debt himself. It is not permissible to directly waive the debt and count it as zakat.