Who is the one required to slaughter the 'aqīqah?
All praise is due to Allah, and may peace and blessings be upon our Master, the Messenger of Allah.
It is Sunnah for the 'aqīqah to be slaughtered by the guardian of the newborn — the one upon whom the child's financial maintenance is obligatory — provided he is financially capable of doing so. 'Alī ibn Abī Ṭālib, may Allah be pleased with him, reported: "The Messenger of Allah ﷺ performed the 'aqīqah for al-Ḥasan with one sheep." — Narrated by al-Tirmidhī. And Allah Almighty knows best.
What is the Sharia basis of the Udhiyah?
Praise be to Allah, and peace and blessings be upon our Master, the Messenger of Allah.
The Sharia basis of the Udhiyah (sacrificial offering) is firmly established through the Quran, the Sunnah, and the Consensus (Ijma') of the Muslims:
1. Evidence from the Holy Quran
Allah the Exalted says {what means}: "And the camels and cattle We have appointed for you as among the symbols of Allah; for you therein is good." [Al-Hajj/36]. He also says {what means}: "So pray to your Lord and sacrifice [to Him alone]" [Al-Kawthar/2]. According to the most well-known scholarly interpretations of this verse, "prayer" refers to the Eid prayer, and "sacrifice" refers to the slaughtering of the Udhiyah.
2. Evidence from the Sunnah
Al-Bara' bin 'Azib (may Allah be pleased with him) narrated that the Prophet ﷺ said: "The first thing we start with on this day of ours is to pray, then we return and sacrifice. Whoever does that has followed our Sunnah, and whoever slaughters before [the prayer], it is merely meat he has provided for his family; it is not part of the ritual sacrifice in any way" [Reported by Bukhari & Muslim].
Anas (may Allah be pleased with him) narrated: "The Prophet ﷺ sacrificed two white rams with horns. He slaughtered them with his own hand, mentioned the name of Allah (Tasmiyah), and said the Takbir" [Reported by Bukhari & Muslim].
3. Evidence from Scholarly Consensus (Ijma')
The Muslims have reached a unanimous consensus on the Sharia basis of the Udhiyah, and no one among the scholars has disagreed with this. [Al-Sherbini, Mughni al-Muhtaj, Vol.6/P.122].And Allah the Exalted knows best.
What is the ruling on praying alone (munfaridan) in a row, and what should I do if I enter the mosque together with another person, and there is only a single gap in the first row with no second row present — should I fill that gap in the first row, or should I stand together with him in a new second row?
All praise is due to Allah, and peace and blessings be upon our master, the Messenger of Allah ﷺ.
If a person enters [the congregation] and finds no space available in the row, it is recommended for him — after making his opening takbīr for the prayer — to gently pull someone from the row in front of him to pray alongside him, provided he senses that this person would be agreeable to it. If that person does not agree, then he prays alone, and there is no dislike attached to his doing so in that case.
If he ends up praying alone [behind the row], it is sunnah for him to stand directly behind the imam. Then, if someone else arrives, that person stands to his right; and whoever comes after them stands to his left — and so on — such that the imam remains centered in the middle of the row. This is done so that everyone attains the reward of congregational prayer.
As for the case where two people enter the prayer together, and there is a gap in the row wide enough for only one person, then the two of them should pray together in a new row [of their own], and whoever arrives after them should fill that original gap. This is because if only one of the two fills the gap, the other would end up praying alone [which is to be avoided when it can easily be prevented].
Al-Khaṭīb ash-Shirbīnī (raḥimahullāh) said in Mughnī al-Muḥtāj (Vol.1/P.494): "If he does not find space, then it is recommended for him, while still standing, to gently pull a single person from the row toward himself after making his opening takbīr — out of caution, so as to avoid the position held by some scholars that a person's prayer standing alone behind the row is not valid.
Az-Zarkashī and others said: this should only be done if it seems he would agree to it; otherwise, he should not pull anyone — indeed, doing so becomes impermissible, out of fear of causing discord (fitnah). It is recommended for the person being pulled to cooperate and agree, so that he may attain the reward of assisting in righteousness and piety (al-birr wat-taqwā). However, he should not pull one of two people [praying together] from the row, since this would cause one of them to end up praying alone. This is why the 'pulling' described here takes place only after the opening takbīr [i.e., once the person doing the pulling has already validly begun his own prayer]."
Accordingly: it is sunnah for you to pray alongside the person praying alone, and then, if someone else arrives afterward, you may go and fill the gap in the original row. And Allah, the Exalted, knows best.
Why was the exact date of Laylat al-Qadr concealed?
The wisdom behind this is to encourage Muslims to strive in worship throughout all the nights of Ramadan, or at least in the last ten nights. By doing so, they will earn the reward of observing Laylat al-Qadr as well as the reward of worshiping on other blessed nights.