What is the semi-circular structure attached to the Holy Kabah?
The semi-circular structure attached to the Holy Kabah is Hijr Al-Kabah (is a low wall originally part of the Kabah) and passing behind it is an obligation while making Tawaf because it is a part of the Holy Kabah. And Allah Knows Best.
Is it a condition for I‘tikaf to be performed in the mosque?
Yes, for I‘tikaf to be valid, it must be performed in a mosque. I‘tikaf is not valid if performed at home or elsewhere.
What are the Sunnah acts of fasting?
● Delaying Suhoor (pre-dawn meal) as long as there is no risk of Fajr beginning.
● Hastening Iftar (breaking the fast) immediately after confirming sunset.
● Performing I‘tikaf, especially during the last ten nights of Ramadan.
● Reciting the Quran frequently.
● Avoiding idle and useless talk.
● Being generous and charitable.
● Guarding oneself from desires.
● Purifying oneself from major impurity (janabah) before Fajr.
Can someone who begins a voluntary fast break it?
It is preferable for someone who begins an act of worship not to break it.
Allah the Exalted has said {what means}: "and let not your [good] deeds come to nought!" [Muhammad/33].
However, if a person starts a voluntary fast (nafl) and needs to break it, they are going against what is preferable, but there is no sin upon them.