Is it permissible for me to take from the Zakat of my father, from whom I borrowed money that has reached its hawl (one year) and nisab (threshold), especially given my poverty and my being a student of Islamic knowledge, and considering that I did not succeed in the purpose for which I borrowed the money?

It is not permissible for a father to give zakat to his poor son if supporting him is obligatory upon the father, because by doing so, he would be shirking an obligation and protecting his own wealth. If the son is capable of earning but his dedication to seeking knowledge prevents him from doing so, and he is a diligent student, then his father is obligated to support him. It is not permissible for the father to give zakat to his son from the share designated for the poor. However, he may give it to him from the share designated for those in debt (al-gharimin), and in that case, the son may benefit from it and settle his debt, whether the debt is owed to the father or to someone else.