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.
Is the marriage, which lacks a valid legal contract, a guardian, and a court registration, valid?
It is incumbent that a valid marriage contract be concluded in the presence of a guardian and two trustful witnesses, and it should be registered in the court to protect the rights of the wife. Actually, a valid marriage contract is what differentiates between sound marriage and fornication.
What is the ruling on deliberately breaking the fast while being capable of fasting?
Whoever intentionally breaks their fast in Ramadan without a valid excuse has committed a major sin and bears great guilt. They must repent, seek forgiveness, refrain from eating and drinking for the rest of the day, and make up for that day after Ramadan.
They have lost an immense reward, which cannot be compensated even by fasting an entire lifetime as a voluntary act, because an obligatory fast cannot be equaled by voluntary fasting.
If the fast was broken through sexual intercourse, the person must:
● Make up for the missed fast (qada), and
● Perform kaffarah by fasting two consecutive months.
● If they are unable to do so, they must feed sixty needy people.
Is the son of the sister by breastfeeding considered a mahram in Islam, and is it permissible for a woman to go for Hajj with him?
Everything that is prohibited by lineage is also prohibited by breastfeeding. The son of the sister by breastfeeding is considered a mahram, just like the son of the sister by blood, and it is permissible for him to be her mahram for Hajj and Umrah. And Allah Knows Best.