Is the father a Mahram (Non-marriageable) to his son`s mother-in-law?
The father is a non-Mahram (Marriageable) to his son`s mother-in-law, so it is impermissible for them to look at each other, or to have a seclusion (Khalwah).
Does post-natal bleeding (Nifas) stop before forty days after childbirth?
Praise be to Allah, and peace and blessings be upon our Master, the Messenger of Allah.
Yes, post-natal bleeding (Nifas) can cease before the completion of forty days. If the bleeding stops completely and its return is not expected, the woman has attained ritual purity (Taharah), even if forty days have not yet passed. And Allah the Exalted knows best.
What is the ruling on intramuscular injections? Do they break the fast?
Therapeutic injections administered under the skin or into the muscles do not break the fast, as they do not enter the body cavity (jauf) through an open passage.
However, intravenous (IV) injections that provide nourishment do break the fast because they function like food and drink in effect.
What is the ruling of Islamic Law on eating or drinking during the circumambulation?
All praise is due to Allah, and peace and blessings be upon our master the Messenger of Allah ﷺ.
It is disliked (makrūh) to eat or drink during the circumambulation (ṭawāf).
Shaykh al-Islām Imām al-Nawawī states in al-Majmūʿ: "It is disliked to eat or drink during ṭawāf, and the dislikedness of drinking is lighter. Neither of them, nor both together, invalidates the ṭawāf. Al-Shāfiʿī said: 'There is no objection to drinking water during ṭawāf, and I do not consider it sinful; however, I prefer that it be avoided, as refraining from it is more befitting in terms of proper conduct.' Among those who explicitly stated the dislikedness of eating and drinking, and that drinking is the lesser of the two, is the author of al-Ḥāwī."
If, however, a person is in genuine need of drinking, then there is no dislikedness in doing so. In any case, the ṭawāf itself remains valid. And Allah the Almighty knows best.