Is it permissible to give multiple mudds (portions) of fidyah to a single person?
Yes, it is permissible to give multiple mudd of fidyah to a single person, because each day of fasting is considered an independent act of worship.
Is washing the private part after urinating (Istinjaa`) a condition, and is it done with water and soap, or with water only?
Istinjaa` is obligatory for removing impurity, and it can be done with toilet paper, or a stone, or water. It is preferable to do Istinjaa` first with paper, or stone, or the like, then to wash the private part with water until making sure that the impurity has been removed. Using soap is not a condition, but there is no harm in doing so provided that it is washed off with water. It is also permissible to use either water, or paper if impurity is removed by any.
My father has debts and asked me to repay them years ago, and I promised him I would do so upon his death — is it permissible for me to go back on my promise given that I am unable to repay them, especially since he refuses to contribute to repayment on the grounds that the debt has become my responsibility by virtue of my promise?
All praise is due to Allah, and peace and blessings be upon our master the Messenger of Allah ﷺ.
The established principle is that a father's debt is to be repaid from his own wealth, if he possesses sufficient means. As for the promise made by the son to repay it on his father's behalf, fulfilling such a promise is strongly recommended, and breaking it is considerably disliked. Shaykh al-Islām Imām al-Nawawī, may Allah have mercy upon him, states: "Fulfilling a promise is emphatically recommended, and breaking it is severely disliked. The evidences for this from the Qurʾān and the Sunnah are well known." [Rawḍat al-Ṭālibīn,Vol. 2/P.278] Shaykh al-Islām Imām Zakariyyā al-Anṣārī, may Allah have mercy upon him, further states: "The reason fulfilling a promise is not obligatory and breaking it is not forbidden is that a promise is in the nature of a gift, and a gift does not become binding except upon receipt." [Asnā al-Maṭālib fī Sharḥ Rawḍ al-Ṭālib,Vol. 2/P.487]
Given that the son does not possess the financial means to fulfil his promise to his father, breaking this promise falls beyond his capacity — and Allah does not burden a soul beyond what it can bear. Since the father himself possesses sufficient wealth to settle his own debt, repayment must be made from his own funds. Should he pass away before doing so, the debt is to be settled from his estate. And Allah the Almighty knows best.
Is it obligatory to make up all missed prayers?
All praise is due to Allah, and peace and blessings be upon our master the Messenger of Allah ﷺ.
Making up missed prayers (qaḍāʾ) is a sharʿī obligation, established by the practice of the Prophet ﷺ himself — when the disbelievers preoccupied him on the Day of the Trench and he missed the ʿAṣr prayer, he made it up afterward. This is further affirmed by the ḥadīth: "Fulfil what you owe to Allah, for Allah is most deserving of being fulfilled." (Reported by al-Bukhārī.)
Accordingly, a person who has missed prayers should set aside his voluntary and Sunnah prayers and replace them with make-up prayers in their stead. There is no objection to making up one missed prayer alongside each obligatory prayer that is performed — praying the equivalent missed prayer together with each current obligatory prayer as a practical and manageable way of gradually clearing one's debt of missed prayers. And Allah the Almighty knows best.
