Is it permissible to offer mandatory prayer while sitting?
All perfect praise be to Allah, The Lord of The Worlds, and may His Peace and Blessings be upon our Prophet Muhammad and upon all of his family and companions. Standing up is a pillar in the mandatory prayer and the prayer is not valid without it unless one cannot do it. As for Nafila (supererogatory prayer), one can perform it in the state of sitting even if he/she can stand, but his/her reward is half the reward of the person who prays while standing if he/sh has no legal excuse for such an act. And Allah Knows Best.
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.
What is the ruling on the follower`s prayer if the Imam stands for a fifth rak`ah?
Praise be to Allah, and peace and blessings be upon our Master, the Messenger of Allah.
If the Imam stands up for an extra unit (rak‘ah) of prayer out of forgetfulness, he must return to the sitting position as soon as he remembers, and he should perform the prostration of forgetfulness (Sujud al-Sahw). It is the duty of the congregants (Ma’mumin) behind him to remind him. However, if the Imam is in a state of doubt regarding the extra unit (and not certainty), it is not permissible for him to return.
As for the congregants: anyone who is certain that the Imam has stood for an extra unit is forbidden from following him. In this case, the follower has two choices: either intend to separate from the Imam (Mufaraqah) and finish the prayer alone, or wait for the Imam in the sitting position and perform the final salams with him—the latter being the preferred option. If a follower knowingly follows the Imam into an extra unit, their prayer becomes invalid. However, if a follower is in doubt and not certain of the mistake, they must continue following the Imam, as the Imam was appointed to be followed.
It is stated in Al-Majmu’ (Vol.4/P.145): 'If [the Imam] stands for a fifth rak‘ah, the follower should not follow him, even if it is assumed that the Imam might have omitted a pillar from a previous unit; because if the reality is known, following him is impermissible since the follower has certainly completed their own prayer. Even if the follower had missed a previous unit (Masbuq) or was in doubt about performing a pillar like the Fatihah, and the Imam stood for the fifth, it is not permissible for the latecomer to follow him in it. This is because we know that this unit is not counted for the Imam and that he is mistaken in performing it.' And Allah the Exalted knows best.
What is the ruling on kidney dialysis while fasting in Ramadan?
Kidney dialysis breaks the fast because the dialysis fluid is nutritive, as confirmed by medical experts. Additionally, it involves the entry of substances into the body cavity (jauf).
A patient undergoing dialysis must make up for that day after Ramadan. If they are unable to do so, they must pay fidyah by feeding one needy person for each day they missed.