What is the ruling on performing the standing (qiyām) and bowing (rukū‘) portions of the prayer normally, while performing the prostration (sujūd) seated due to knee pain?
All praise is due to Allah, and peace and blessings be upon our master, the Messenger of Allah ﷺ.
If performing sujūd (prostration) in prayer causes the worshipper pain in the knees, then it is permissible for him to perform it through gesture (īmā') while seated, since Allah, Glorified and Exalted is He, has lifted hardship from His servants. On the authority of ‘Imrān ibn Ḥuṣayn (raḍiyallāhu ‘anh), he said: "I suffered from hemorrhoids, so I asked the Prophet ﷺ about [how to perform] the prayer, and he said: 'Pray standing; if you are unable, then sitting; and if you are unable, then on your side.'" [Ṣaḥīḥ al-Bukhārī]
If the valid excuse later subsides, the worshipper is then obligated to perform the prayer with all its pillars and conditions fully observed — including standing, rukū‘ (bowing), and sujūd (prostration). And Allah, the Exalted, knows best.
What is the ruling on the intention of fasting, where is its place, and when is its time?
The intention is a pillar of acts of worship; it is essential, and worship is not valid without it.
Its place is in the heart, and verbalizing it is recommended so that the tongue reminds the heart. Its meaning is to be determined to abstain from nullifiers of fasting during the upcoming day with the intention of worship and obedience to Allah Almighty. This meaning is naturally present in every Muslim on every night of Ramadan, so there is no need for obsessive doubts. If one says, "I intend to fast tomorrow for the sake of Allah," it removes any doubts.
Its time is from after sunset until before the true dawn.
There are olive trees within the precincts of the mosque, and my father covers the costs of electricity, water, and other needs of the mosque. Is it permissible for him to take the olive harvest?
All praise is due to Allah, and peace and blessings be upon our master, the Messenger of Allah.
If trees and fruit-bearing crops are planted in a mosque for the mosque itself, they may only be spent on the mosque’s interests. If they were planted for the public way (musabbalah), that is, for the general public, then any Muslim who enters the mosque may eat from them. If the planter’s intention is unknown, they are treated like those dedicated for public use, wherever custom has so run.
It is stated in Tuḥfat al-Muḥtāj (Vol.6/p.295): “The fruit of a tree planted for the mosque within it is not freely permitted without compensation. Rather, the imam spends its equivalent value on the mosque’s interests. The tree left its planter’s ownership here without any verbal declaration because of the evident indication. The case of planting it for the mosque excludes planting it as musabbalah, in which case eating from it without compensation is permissible, and likewise if his intention is unknown, where custom has so run. The tree may be uprooted from the mosque if the imam sees fit. Indeed, if he makes the plot a mosque while a tree stands in it, the imam may uproot it, even if the endower included it within the endowment (waqf).”
The father is a donor (mutabarriʿ), so he is not entitled to take anything in return for his donation to the mosque.
The Ministry of Awqāf is the body that supervises the affairs of endowments, so it must be consulted and the Sharīʿah and administrative instructions regulating such matters must be considered. And Allah Almighty knows best.
Is it permissible for the children of a deceased father to settle his debt from the Zakah (obligatory charity) money due on them?
It is impermissible to use the Zakah of one`s money for settling the debts of the deceased. However, children should settle the debts of their deceased parents out of filial piety. And Allah Knows Best.