Does the clipping of nails nullify ablution?
No, it does not, and it is preferable to wash the hands afterwards.
Is it permissible to trim the eyebrows if they become excessively long?
Trimming eyebrows is permissible if they become excessively long, yet; it is reprehensible. And Allah 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.
What does "All the deeds of the son of Adam are for him, except fasting" mean?
The Prophet ﷺ said: "Allah, the Almighty, said: 'Every deed of the son of Adam is for him, except for fasting; it is for Me, and I shall reward for it." [Agreed upon]
This means:
● Every deed of the son of Adam may be affected by showing off (riyaa’), except fasting, because only Allah knows whether a person is truly fasting or not.
● The reward for all deeds is known—one good deed is multiplied tenfold—except fasting, as only Allah knows its true reward.
