What is the ruling on fasting only on Friday, Saturday, or Sunday?
In voluntary fasting (nafl), it is disliked (makruh) to fast only on Friday, Saturday, or Sunday.
However:
● If one fasts a day before or after Friday, then that is permissible.
● The same applies to Saturday and Sunday—fasting them along with another day removes the dislike.
● Fasting all three days (Friday, Saturday, and Sunday) together is not disliked.
If any of these days coincide with a recommended fasting day, such as Arafah or Ashura, then fasting it alone is not disliked.
Must a person refrain from eating for the rest of the day if they break a fast of a vow (nadhr) or a make up fast (qada)?
Whoever observes a vowed fast (nadhr) or a makeup fast (qada) is prohibited from breaking it without a valid excuse. If they break it without a legitimate reason, they are sinful.
However, they are not required to refrain from eating for the rest of the day, because such restraint is only required out of respect for the month of Ramadan, not for other types of fasting.
Should a prayer performer who forgets to offer the middle Tashahod (saying ash-hadu anala ilaha ila-alah) offer Sujood As-Sahw (prostration of forgetfulness)?
He/she should offer two prostrations of forgetfulness at the end of the prayer. And Allah Knows Best.
What is the ruling on performing istinja' with perfumed tissues or a tissue moistened with water?
Performing istinja' with perfumed or moistened tissues is not sufficient if they are not dry, due to the moisture on them reaching the impurity, which increases its spread rather than reducing it. Then, to remove the impurity, one must use pure water. And Allah the Almighty knows best.