What is the ruling on someone who intends to travel to Jeddah for two days — must he enter iḥrām from his place of residence [i.e., before passing the mīqāt]?
All praise is due to Allah, and peace and blessings be upon our master, the Messenger of Allah ﷺ.
Whoever is firmly resolved in his intention to perform ‘Umrah before setting out on his journey, it is unlawful for him to pass beyond his country's mīqāt (the designated boundary point for entering the state of iḥrām) without entering iḥrām. If he does so, he must return to the mīqāt to enter iḥrām from there, provided he has not yet begun performing the rites of the pilgrimage — in which case nothing further is required of him. However, if he does not return, he must offer a sacrifice (sheep/goat), to be distributed among the poor of the Ḥaram.
It is stated in at-Tanbīh fī al-Fiqh ash-Shāfi‘ī (p. 71): "Whoever, intending to perform the rites [of ‘Umrah or Ḥajj], passes beyond the mīqāt and enters iḥrām only after it, must offer a sacrifice. However, if he returns to the mīqāt before beginning any of the rites, the sacrifice is waived from him."
Accordingly: whoever is firmly resolved in his intention to perform ‘Umrah before setting out on his journey must enter iḥrām at the mīqāt of his country through which he passes. Whoever fails to do so, passing beyond the mīqāt without entering iḥrām, and does not return, has sinned, and must repent to Allah, the Exalted; and he must offer a sacrifice, to be distributed among the poor of the Ḥaram. And Allah, the Exalted, knows best.
What is the ruling on water that contains ornamental fish — does it become impure on account of their waste?
All praise is due to Allah, and peace and blessings be upon our master the Messenger of Allah ﷺ.
The water in a pond containing ornamental fish is pure so long as it has not been altered, for a small amount of fish waste (rawth) is pardoned and overlooked — provided it does not change the water.
It is stated in Ḥāshiyat al-Jamal ʿalā Sharḥ al-Manhaj (Vol.1/P.178): "A small amount of hair from a non-edible animal is pardoned, as is a small amount of hair from a riding animal — on account of the hardship involved in avoiding it — and likewise a small amount of fish waste is pardoned, unless it alters the water." And Allah the Almighty knows best.
What is the ruling on congregational prayer performed outside the mosque, and is it a condition that it be performed in a mosque in order to attain the full reward?
All praise is due to Allah, and peace and blessings be upon our master, the Messenger of Allah ﷺ.
It is not a condition for attaining the reward of congregational prayer that it be performed in a mosque; however, a Muslim should still be keen to perform his prayers in the mosque, so as not to miss out on immense reward. This is due to the virtue of the mosque and of spending time there (i‘tikāf), the typically larger number of worshippers present, and the additional reward gained through walking to and from the mosque. On the authority of Abū Hurayrah (raḍiyallāhu ‘anh), the Messenger of Allah ﷺ said: "Whoever purifies himself in his house, then walks to one of the houses of Allah to fulfill one of the obligations Allah has prescribed, one of his steps will erase a sin, and the other will raise him a degree [in status]." (Related by Muslim)
Whoever misses congregational prayer at the mosque should still strive to pray in congregation at his workplace, or together with the members of his household. And Allah, the Exalted, knows best.
Is it permissible for a husband to stop his wife from visiting her family?
A husband shouldn`t stop his wife from visiting her family, and it is disliked for him to do so because such an act makes them harbor feelings of hatred against him.