Is it permissible for a woman to wear underwear while performing Umrah?
Yes, it is permissible for a woman to wear underwear while performing Umrah. This is because she should keep her regular clothes that cover all her body while being in a state of Ihram (ritual consecration) for Hajj, or Umrah. However, she should uncover her face and hands, but it is permissible for her to let her head-covering garment drape from her head down over her face when non-Mahram (i.e., marriageable) men pass by her. And Allah Knows Best.
Is it permissible for a wife to give her money to her family as a charity, or a gift without asking her husband, or seeking his consent?
The wife has the right to give her money as a charity, or a gift to her family, or to other people after consulting her husband out of respect, and this is the meaning of treating on footing of kindness and equity. Therefore, if he wanted to stop her from helping her family, then there is no harm in not telling him.
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.
What is the monetary value for the expiation of an oath (Kaffarat al-Yamin)?
Praise be to Allah, and peace and blessings be upon our Master, the Messenger of Allah.
The expiation for an oath (Kaffarat al-Yamin) consists of feeding ten (10) needy persons. This is estimated at 600 grams of rice per person. It is also permissible to pay its value in cash, which is estimated at one dinar (per person). And Allah the Exalted knows best.