What are the Sharia consequences when the sacrificial time for the uḍḥiyyah comes to an end?
All praise is due to Allah, and may peace and blessings be upon our Master, the Messenger of Allah.
If the sun sets at the end of the last of the Days of Tashrīq and the sacrificial animal (uḍḥiyyah) has not yet been slaughtered, then its prescribed time has elapsed. Should one slaughter it thereafter, it will not be considered a valid uḍḥiyyah.
However, if the sacrifice was vowed (mandhūrah), then it remains obligatory to slaughter it — and it shall be carried out as a make-up (qaḍā') of the vow, with its meat distributed in the rightful channels designated for such sacrifices.
It is stated in Bushrā al-Karīm (p. 702): "If one slaughters after the sunset of the last of the Days of Tashrīq... it isn`t considered a valid uḍḥiyyah, unless it was vowed — in which case it is carried out as qaḍā'."
And Allah Almighty knows best.
Which is better during the day in Ramadan: reciting the Quran or performing voluntary prayers?
A Muslim should establish a daily schedule for reciting the Quran in Ramadan.
Once they have completed their daily portion (known as a wird or hizb), they can engage in other acts of worship, including voluntary prayers (nawafil). Prayer itself is called "Quran", because a significant part of it involves reciting the Quran.
Allah says: "BE CONSTANT in [thy] prayer from the time when the sun has passed its zenith till the darkness of night, and [be ever mindful of its] recitation at dawn: for, behold, the recitation [of prayer] at dawn is indeed witnessed [by all that is holy]." [Al-Isra`/78]
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.
Is it permissible for one to give the Zakah (obligatory charity) to his indebted brother?
It is permissible for one to give the Zakah to his brother if he was indebted, or poor.
