Is it permissible to sleep before the time of the Fajr prayer begins, with the intention of waking up shortly afterward?
All praise is due to Allah, and peace and blessings be upon our master, the Messenger of Allah.
It is permissible for a Muslim to sleep before the time of the Fajr prayer begins, intending to wake up and perform the prayer, by setting an alarm or asking someone to wake him. What is to be avoided is that a person sleeps while he predominantly assumes that he will not wake up for the prayer.
If he does not wake up until the time of the prayer has ended, he must make it up. It is recommended that he hasten to make it up as soon as he wakes, and likewise recommended that he make up its sunnah along with it.
It is stated in al-Majmūʿ by Shaykh al-Islām Imam al-Nawawī (may Allah have mercy on him): “Whoever was obliged to pray and did not pray until the time passed must make it up, because of the saying of the Prophet (peace and blessings be upon him): ‘Whoever sleeps through a prayer or forgets it, let him pray it when he remembers it.’ It is recommended that he make it up immediately, because of the ḥadīth we have mentioned. If he delays it, that is permissible, because it is reported that the Prophet (peace and blessings be upon him) missed the Fajr prayer and did not pray it until he had left the valley. Had it been required immediately, he would not have delayed it. Abū Is-ḥāq said: If he left it without a valid Sharia excuse, he must make it up immediately, because he was negligent in delaying it.”
It is therefore the duty of every Muslim to keep the prayer in its proper time, seeking help from Allah the Exalted and striving against the self to do so. And Allah Almighty knows best.
A woman made a wig for herself from her own [previously shed] hair, which she wears on her head after having lost her hair [due to hair loss]. Is this permissible?
All praise is due to Allah, and peace and blessings be upon our master, the Messenger of Allah ﷺ.
Since the hair belongs to the woman herself, the wig can be removed during the obligatory ghusl (ritual bathing), and part of the head can still be wiped during wuḍū' (ablution), there is no sharī‘ah objection to making this wig — provided she does not appear wearing it in front of non-maḥram men (Any males outside a woman's immediate family whom she is permitted to marry under Islamic law), since it is not permissible for them to look at a woman's detached hair.
It is stated in Rawḍat aṭ-Ṭālibīn wa ‘Umdat al-Muftīn: "Whatever it is not permissible to look at while still attached [to the body] — such as the male genitalia, a free woman's forearm, the hair of her head, and a man's pubic hair, and similar matters — it remains unlawful to look at even after it has been detached [from the body], according to the more correct position (al-aṣaḥḥ)." And Allah, the Exalted, 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.
Can I start fasting based on the moon sighting of another country?
You must follow the moon sighting of the country you are in.