What are the pillars of fasting?
The pillars of fasting are intention and abstaining from all nullifiers of fasting from dawn to sunset.
How to perform the witr prayer in terms of connection (wasl) and separation (fasl)?
Praise be to Allah, and peace and blessings be upon our Master, the Messenger of Allah.
The Witr prayer has several forms that vary in terms of virtue:
The First Form: Separating every two units (rak‘ah) with a Tashahhud and a Taslim (salutation). This is superior to connecting the units, even if it is only a single rak‘ah. This is based on the Hadith of ‘Aishah (may Allah be pleased with her): 'The Messenger of Allah ﷺ used to pray eleven units between the end of the ‘Isha prayer and dawn, performing the Taslim after every two units and performing Witr with a single unit.' (Related by al-Bukhari & Muslim).
The Second Form: Connecting the units with only one final Tashahhud at the very end.
The Third Form: Connecting with two Tashahhuds—meaning reciting the Tashahhud before the final unit without performing the Taslim, then standing to complete the final unit. This form is considered the lowest in rank so that the Witr prayer remains distinct from the obligatory Maghrib prayer, as stated in the Hadith: 'Do not make the Witr resemble the Maghrib prayer.' (Narrated by Al-Daraqutni, who stated its narrators are trustworthy).
It is stated in Bushra al-Karim Sharh al-Muqaddimah al-Hadramiyyah: 'It is permissible to connect [the Witr] with one Tashahhud in the final unit—which is better—or with two Tashahhuds in the last two units, as both methods are established in Sahih Muslim from the actions of the Prophet ﷺ. In the connected method, more than two Tashahhuds are prohibited. Furthermore, separating (al-Fasl) is better than connecting (al-Wasl) if the number of units is the same, because the Hadiths supporting it are more numerous and it involves more devotional actions.' And Allah the Exalted knows best."
Is it permissible to eat from an Udhiyah slaughtered on behalf of a deceased person?
Praise be to Allah, and prayers and peace be upon our Master the Messenger of Allah.
It is permissible to eat from the sacrifice (uḍḥiyyah) that is offered on behalf of a deceased person. This is the madhhab (school of thought) of the Hanbalis. In this case, the heirs take the place of the deceased as if he were alive, with the same rights to eat from it, give it in charity, and offer it as a gift.
It is stated in Maṭālib Uli al-Nuhā (Vol.2/P.472): "Offering a sacrifice on behalf of a deceased person is better than offering one on behalf of a living person, because the deceased is unable (to perform deeds) and is in need of reward. It is to be treated like a sacrifice on behalf of a living person in terms of eating, giving charity, and giving gifts." And Allah Almighty knows best.
What is the meaning of the Prophetic statement that a boy is held in pledge (murtahan) for his 'aqīqah?
All praise is due to Allah, and may peace and blessings be upon our Master, the Messenger of Allah.
The first interpretation: That if the boy dies in infancy without an 'aqīqah having been performed on his behalf, he will not intercede for his parents on the Day of Resurrection. This is the position of Imam Aḥmad ibn Ḥanbal, and Imam al-Khaṭṭābī concurred with him, stating: "The finest of what has been said regarding this matter is the position adopted by Aḥmad ibn Ḥanbal." — [Fatḥ al-Bārī by Ibn Ḥajar,{Vol.9/P.594]
The second interpretation: That the child is likened to a pledged object (marhūn) — one from which full benefit and enjoyment cannot be derived until it is redeemed. A blessing is only made complete upon the one blessed when they fulfil the obligation of gratitude (shukr), and the prescribed expression of gratitude for this particular blessing is what the Prophet ﷺ established as Sunnah — namely, the slaughtering of the 'aqīqah on behalf of the newborn as an act of thankfulness to Allah the Almighty and as a supplication for the wellbeing and safety of the child. This is the position of Mullā 'Alī al-Qārī. See: [Mirqāt al-Mafātīḥ Sharḥ Mishkāt al-Maṣābīḥ, Vol.7/P.2688]
And Allah Almighty knows best.