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.
If someone delays making up fasts for a year, can they give fidyah before performing qada?
Yes, it is permissible to give fidyah before making up the missed fasts (qada), because each is an independent obligation, and there is no required order between them.
What is the ruling if a postpartum woman becomes pure before forty days; are acts of worship obligatory upon her, and is she permissible for her husband?
If the postpartum woman becomes definitely pure before forty days, she must perform the ritual bath and perform acts of worship as a pure woman does. What was prohibited for her also becomes permissible, so she becomes permissible for her husband after her bath. The minimum duration for postpartum bleeding is a moment (an instant), and its usual maximum is forty days. Reaching forty days is not a condition; rather, it is sufficient for the blood to stop or to see the white discharge (qassa bayda'). And Allah the Almighty knows best.
Is it permissible to agree with a butcher to purchase the meat of an animal after it has been slaughtered — for instance, by buying the meat of a sheep at a price determined by the weight of its meat following slaughter, at a fixed rate per kilogram? And what is the ruling if the animal is being purchased with the intention of it being an uḍḥiyyah (sacrificial offering)?
All praise is due to Allah, and may peace and blessings be upon our Master, the Messenger of Allah.
It is not permissible to sell livestock in the manner of pricing each kilogram of meat after slaughter at a fixed rate, because the meat within the animal prior to slaughter is unseen and unknown. This leads to jahālah (ignorance of the subject matter) and gharar (contractual uncertainty), both of which are among the invalidating factors in sales transactions.
However, it is permissible for the buyer to issue a promise to purchase the meat of the animal after slaughter at a specified price per kilogram, with the actual sale being concluded at the time of weighing the meat — at which point both the quantity of the goods and the total price become known. There is no Sharī'ah objection to this arrangement.
The jurists have stipulated that for a sale to be valid, both countervalues must be present and observable. Al-Khaṭīb al-Shirbīnī, may Allah have mercy upon him, states:
"It is valid to sell a heap of grain whose total measure is unknown to both contracting parties at a rate of one sā' per dirham. This sale is valid because the subject of sale is present and observable, and ignorance of the total price is not harmful since it is known in detail — and uncertainty is thereby lifted."— [Mughnī al-Muḥtāj, Vol.2/P.355]
As for the uḍḥiyyah, the 'aqīqah, and vowed blood sacrifices (al-dam al-mandhūr) — full ownership of the animal must be established prior to slaughter. It is not valid for such animals to be slaughtered while still in the ownership of the butcher. Rather, the animal must be purchased alive and then slaughtered with the intention of uḍḥiyyah or the like. And Allah Almighty knows best.