What is the ruling on taking a loan from an interest-based bank (a usurious bank) to buy an apartment for housing, noting that I am renting at a high amount relative to my income, and I am an employee? Also, considering that the conditions of Islamic banks are strict, and I cannot obtain the full amount from them, is it permissible to take a loan to purchase an apartment or not? May Allah reward you.
Usury (interest) is prohibited by Islamic law, and the Messenger of Allah, peace be upon him, cursed the one who consumes usury, the one who pays it, its recorder, and its witnesses. Whoever leaves something for the sake of Allah, Allah will compensate them with something better and greater, and Allah will provide relief after hardship. Needing a place to live does not permit taking a loan with interest. And Allah Knows Best.
Is it permissible to listen to chants praising the Prophet if accompanied by musical instruments?
If singing, or chanting in praise of the Prophet was accompanied by a forbidden musical instrument, then it is forbidden.
Is Iddah (waiting period) incumbent on an old woman whose husband had died?
Upon the death of the husband, Iddah is incumbent on the wife regardless of their age. And Allah Knows Best.
How is night prayer offered?
Night prayer is offering voluntary prayer after Maghrib and before Fajr (Dawn). As for Tahajjud, it is offering voluntary prayer at night after waking up voluntarily, and for Allah`s sake as He Says (What means): "And pray in the small watches of the morning: (it would be) an additional prayer (or spiritual profit) for thee: soon will thy Lord raise thee to a Station of Praise and Glory!" [Al-Isra`/79]. Offering Tahajjud is better than offering voluntary prayer before going to bed.