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.
Is it permissible for a menstruating woman to recite the Quran from the computer without actually touching the Quran?
It is not permissible for a woman in her menstrual period, or in postpartum to recite the Quran, even by heart, or without actually touching the Quran itself. Recitation itself is what is prohibited on her regardless of how it is done. However, it is permissible for her to surf through the Quran by her eyes, or to recall it in her head without uttering the words. There is no harm for her to look at the Quranic verses on the computer without touching it, or to utter the words as this is called looking not reciting or reading.
If a person enters a mosque and finds the congregation in the final tashahhud, which is more virtuous — joining them or waiting for a second congregation to catch the opening takbīr (takbīrat al-iḥrām)?
All praise is due to Allah, and peace and blessings be upon our master the Messenger of Allah ﷺ.
If a worshipper finds a congregation that is about to finish its prayer, and he hopes to catch the entire prayer from the beginning with another congregation, it is more virtuous for him to pray with this first congregation and then repeat the prayer with the second one — provided he does not intend to confine himself to a single prayer. If, however, he intends to perform only one prayer, then it is more virtuous for him to wait for the second congregation rather than joining the first, so that he may attain the reward of congregational prayer for every single rakʿah.
Al-Khaṭīb al-Sharbīnī, may Allah have mercy upon him, states: "If members of a congregation enter the mosque while the imam is in the final tashahhud, al-Qāḍī Ḥusayn held that it is recommended for them to join him in prayer, and that they should not delay in order to form a second congregation. Al-Mutawallī, however, affirmed the opposite view, and al-Qāḍī's own statement elsewhere supports this latter position, which is the relied-upon view. In fact, it is more virtuous for a person who has missed part of the prayer with one congregation, and who hopes to catch another congregation with whom he can attain the entire prayer within its proper time, to delay so that he may catch it in full with them. This applies when he intends to confine himself to a single prayer; otherwise, it is more virtuous for him to pray with the first group and then repeat the prayer with the others." [Mughnī al-Muḥtāj,Vol. 3/P.186] And Allah the Almighty knows best.
What is the ruling of Islamic Law on eating or drinking forgetfully while observing the kaffarah fasting?
Praise be to Allah, and peace and blessings be upon our Master, the Messenger of Allah.
If someone eats or drinks out of forgetfulness while fasting, it is simply that Allah has fed them and given them drink. Their fast is not broken by this; rather, they should continue fasting. This ruling applies whether the fast is an obligatory one (like Ramadan), a make-up fast (Qada), an expiation (Kaffarah), or a voluntary (Nafal) fast. And Allah the Exalted knows best.