What is the ruling on performing istinja' before every ablution?
Istinja' is not from the conditions for the validity of ablution. It is only obligatory for prayer when there is impurity from urine or stool on the private part, or if there is fear of the impurity spreading to the body or clothing. And Allah the Almighty knows best.
How is the Night Prayer (Qiyam al-Layl) performed?
Praise be to Allah, and peace and blessings be upon our Master, the Messenger of Allah.
Night Prayer (Qiyam al-Layl) refers to the voluntary (Nafl) prayers performed by a person after the Sunset prayer (Maghrib) and before the Dawn prayer (Fajr). As for Tahajjud, it is the voluntary prayer performed during the night specifically after waking up from sleep, as an act of devotion to Allah. Allah the Exalted says {what means}: "And from [part of] the night, pray with it [i.e., recitation] as additional worship for you." (Al-Isra/79). Thus, in terms of reward,Tahajjud is superior to voluntary prayers performed before sleeping. And Allah the Exalted knows best.
Does the 'aqīqah count as valid if it is slaughtered before the seventh day from the birth?
All praise is due to Allah, and may peace and blessings be upon our Master, the Messenger of Allah.
The time during which it becomes permissible to slaughter the 'aqīqah begins from the moment the newborn is fully delivered from its mother's womb.
If the animal is slaughtered prior to the birth, it does not count as an 'aqīqah — it is simply considered an ordinary sheep slaughtered for its meat.
And Allah Almighty knows best.
A pregnant woman has iron deficiency. When she showers, she becomes very tired and feels cold. What is the ruling on tayammum in this situation?
All praise is due to Allah, and peace and blessings be upon our master, the Messenger of Allah ﷺ.
One should not resort to tayammum (dry ablution) as a substitute for the obligatory ghusl (ritual bathing) so long as it remains possible to use water — for example, by heating the water, warming the place where the bathing takes place, or taking other similar precautions. However, if such measures prove ineffective, or are simply not possible to carry out, and performing ghusl [with cold water] would result in severe harm, then tayammum becomes permissible in that case, due to genuine inability to use water on account of the harm that would result, as described in the question. That said, she must make up (qaḍā') the prayers she performed using this tayammum.
It is stated in Bushrā al-Karīm: "One should not perform tayammum on account of cold unless warming the limbs fails to remove the aforementioned harm, and no means are available to heat the water — such as a vessel, firewood, or fire — and one fears [that using cold water would result in] any of the harms mentioned earlier in the discussion on illness: danger to life, loss of function in a limb, the onset or worsening of an illness, delayed recovery, or the [visible bodily] blemish mentioned in that discussion on illness. In such a case, tayammum becomes permissible due to the harm involved, but the prayer must still be made up afterward (qaḍā'). If, however, warming the body proves effective, or the means to heat the water are available, or none of the aforementioned harms are feared — then tayammum is not permissible, even if using the water causes some degree of discomfort or pain, since mere discomfort alone does not permit resorting to tayammum." And Allah, the Exalted, knows best.