Is it permissible to include others in the reward of one`s sacrifice?
In the Name of Allah, and may peace and blessings be upon our Master, the Messenger of Allah.
It is permissible for the person offering an Udhiyah (sacrificial offering) to include others in the spiritual reward of the sacrifice. However, it is not permissible for multiple people to jointly share the purchase price of a single sheep or goat, unless one person gifts the money to the other.
It is stated in Mughni al-Muhtaj (6/137) by Al-Khatib al-Shirbini:
"If a person includes someone else in the reward of his sacrifice and slaughters it on his own behalf, it is permissible."
It should be carefully noted that including someone else in the reward of one's sacrifice is completely distinct from offering a sacrifice on behalf of someone else. And Allah the Almighty Knows Best.
Should nail polish be removed before making ablution?
Yes, it should be removed because it prevents water from reaching the nails.
What is the ruling of Islamic Law on participating in the prize draws (raffles) that commercial stores hold for their customers?
Praise be to Allah, and peace and blessings upon our master, the Messenger of Allah.
There is no objection to participating in the prize draws (raffles) that commercial stores hold for their customers, provided that the buyer's intention in purchasing is not merely to enter the competition without any need for what is bought — rather, the purchase must be genuinely intended for the item itself, and one must not pay more than the item's fair market price. This is because paying an amount above the market price would effectively be paying a fee to enter the prize draw, which would render it a form of gambling (qimār).
These prizes are, in essence, gifts that businesses offer through a random drawing (qur'ah) to those who purchase from them, as a means of encouraging sales, without the customer bearing any additional monetary cost for participation. So long as the aforementioned conditions are met, there is no objection to benefiting from the prize offered by the store, as it is considered a lawful prize from the viewpoint of Islamic Law.
It is stated in the resolutions of the "Jordanian Iftaa' Board" (Resolution No. 47), in the context of outlining the conditions for permissible prizes: "The price of the ticket [or item purchased] for the sake of the prize must not exceed its original price, so that there is no payment of money in exchange for participation in the draw." And Allah, the Most High, knows best.
Is Zakah (obligatory charity) due on articles of merchandise even if they were stacked in the merchant`s stores for years?
Yes, Zakah is due on goods even if they were stacked in merchant`s stores for years, in this manner Islam struggle against monopoly.