Is Zakah (obligatory charity) due on the money saved for marriage?
Zakah is due on the money saved for marriage if it reached the Nissab (minimum amount liable for Zakah), and a whole lunar year had lapsed over possessing it.
Is it permissible for one who sacrifices on behalf of another, with the latter's permission, to eat from the sacrifice?
It is permissible for someone who sacrificed on behalf of another with their permission to eat from it with their permission, and they stand in their place (act as their representative) in distributing it.
It is stated in Nihayat al-Muhtaj ila Sharh al-Minhaj (Vol.8/P.141): "And he—meaning the one sacrificing on his own behalf, provided he has not apostatized—has the right to eat from a voluntary sacrifice and his sacrificial gift; rather, it is recommended. As for an obligatory sacrifice, it is forbidden for him to eat from it, whether it was designated as such initially or as a liability in his dhimmah. And excluded by what has preceded is if he sacrifices on behalf of another, or if he apostatized, then it is not permissible for him to eat from it, just as it is absolutely impermissible to feed a disbeliever from it."(The text I found indicates the impermissibility of eating) ???
And it is stated in Hashiyat al-Jamal ‘ala Sharh al-Manhaj (Vol.5/P.262): "If a person offers a sacrifice on behalf of a living person with their permission, does he act as their representative in distributing it—on the grounds that permission to sacrifice is permission to distribute it—or does it depend on their explicit permission? This requires consideration, but the first view is not far-fetched." And Allah the Almighty knows best.
Which hour coincides with the last third of the night?
This hour could be figured out by calculating the number of night hours which start at sunset, and end at dawn break, then the total is divided on three to get the result.
If someone fasts on the White Days with the intention of making up for missed fasts (qada), will they receive the reward for both voluntary and obligatory fasting?
Making up missed obligatory fasts (qada) is mandatory, and the intention for qada must be specified.
If a person makes up their missed Ramadan fasts on the White Days, they must intend qada, but they may also intend to fast the White Days, and Allah willing, they will receive the reward for both.
This is similar to entering a mosque and praying an obligatory prayer, where the person also earns the reward of Tahiyyat al-Masjid (greeting the mosque) if they intend both.
● If the person missed their fasts due to a valid excuse, they may wait and fast on the White Days.
● However, if they missed the fasts without a valid excuse, they must make up the fasts immediately and should not delay them until the White Days.
