What is the due amount of food in expiation for perjury?
It is feeding ten indigent persons: 600 grams (for each) of the average food of your families such as rice, and it is permissible, according to Imam Ahmad Bin Hanbal, to give that amount in money if it was more useful to them.
What is the ruling on offering an Udhiyah on behalf of another with their permission?
Praise be to Allah, and peace and blessings be upon our master, the Messenger of Allah.
It is permissible for a person to offer a sacrifice (Udhiyah) on behalf of someone else with their permission, even if the person performing it has not offered a sacrifice for themselves. It is stated in Sharh Manhaj al-Tullab (Vol.5/P.261) by Zakariya al-Ansari: "No one may offer a sacrifice on behalf of another without their permission... as opposed to when permission has been granted." And Allah the Almighty knows best.
Is it permissible for a woman to wear underwear while performing Umrah?
Yes, it is permissible for a woman to wear underwear while performing Umrah. This is because she should keep her regular clothes that cover all her body while being in a state of Ihram (ritual consecration) for Hajj, or Umrah. However, she should uncover her face and hands, but it is permissible for her to let her head-covering garment drape from her head down over her face when non-Mahram (i.e., marriageable) men pass by her. And Allah Knows Best.
I work overtime after regular working hours and may become occupied with my phone or the work computer for personal matters — what is the ruling on this?
All praise is due to Allah, and peace and blessings be upon our master the Messenger of Allah ﷺ.
It is obligatory upon an employee to abide by the instructions and regulations governing overtime hours, and equally obligatory to uphold honesty and avoid all forms of deception and dishonesty. Allah the Almighty says {what means}: "O you who have believed, be mindful of Allah and be with the truthful." [Al-Tawbah/ 119]
Whoever is assigned to work overtime must be present at his workplace — even if he has no specific tasks to carry out at that time. In such a case, he should strive as best he can to spend that time in a manner that benefits the institution he works for. If there is genuinely no work for him to do, there is no objection to occupying his time with something beneficial — such as reciting the Holy Qurʾān, reading, or listening to educational lessons — provided he has already completed all the responsibilities assigned to him.
If, however, he does have work to complete, he must spend that time fulfilling it. He may attend to phone calls or other personal matters to the extent that is customarily acceptable, as long as this does not result in delaying or postponing his work. If he delays his work on account of personal preoccupations, the wages he received for that wasted time are not lawfully his to keep, and he is obliged to return the equivalent amount to the institution by whatever means available to him. And Allah the Almighty knows best.