Does using a respiratory device (oxygen) affect the validity of fasting?
Using an oxygen device does not affect the validity of fasting because oxygen is a gas with no physical substance.
However, if medicinal substances with physical particles are added to the oxygen, its use would break the fast, as it enters the body cavity through a natural passage.
What is the ruling on praying alone (munfaridan) in a row, and what should I do if I enter the mosque together with another person, and there is only a single gap in the first row with no second row present — should I fill that gap in the first row, or should I stand together with him in a new second row?
All praise is due to Allah, and peace and blessings be upon our master, the Messenger of Allah ﷺ.
If a person enters [the congregation] and finds no space available in the row, it is recommended for him — after making his opening takbīr for the prayer — to gently pull someone from the row in front of him to pray alongside him, provided he senses that this person would be agreeable to it. If that person does not agree, then he prays alone, and there is no dislike attached to his doing so in that case.
If he ends up praying alone [behind the row], it is sunnah for him to stand directly behind the imam. Then, if someone else arrives, that person stands to his right; and whoever comes after them stands to his left — and so on — such that the imam remains centered in the middle of the row. This is done so that everyone attains the reward of congregational prayer.
As for the case where two people enter the prayer together, and there is a gap in the row wide enough for only one person, then the two of them should pray together in a new row [of their own], and whoever arrives after them should fill that original gap. This is because if only one of the two fills the gap, the other would end up praying alone [which is to be avoided when it can easily be prevented].
Al-Khaṭīb ash-Shirbīnī (raḥimahullāh) said in Mughnī al-Muḥtāj (Vol.1/P.494): "If he does not find space, then it is recommended for him, while still standing, to gently pull a single person from the row toward himself after making his opening takbīr — out of caution, so as to avoid the position held by some scholars that a person's prayer standing alone behind the row is not valid.
Az-Zarkashī and others said: this should only be done if it seems he would agree to it; otherwise, he should not pull anyone — indeed, doing so becomes impermissible, out of fear of causing discord (fitnah). It is recommended for the person being pulled to cooperate and agree, so that he may attain the reward of assisting in righteousness and piety (al-birr wat-taqwā). However, he should not pull one of two people [praying together] from the row, since this would cause one of them to end up praying alone. This is why the 'pulling' described here takes place only after the opening takbīr [i.e., once the person doing the pulling has already validly begun his own prayer]."
Accordingly: it is sunnah for you to pray alongside the person praying alone, and then, if someone else arrives afterward, you may go and fill the gap in the original row. And Allah, the Exalted, knows best.
Is it permissible to offer an absentee funeral prayer?
Yes, it is permissible to offer an absentee funeral prayer.
What is the ruling on tasting food while fasting?
Tasting food while fasting is disliked (makruh). However, if any part of the food reaches the body cavity (jauf), the fast becomes invalid.
