What is the ruling on istibra' and how is it performed?
Istibra' (cleansing from urine) is recommended. It is for a person to ensure that nothing remains of urine in its passage before performing istinja'. Its method is: to clear the throat (or cough slightly), shake the penis (meaning to pass fingers along it to expel any remaining urine if needed), and walk a few steps to the extent that one thinks nothing of urine remains if walking is needed. Each person knows his own nature best. The preferred opinion is that this differs among people. The objective is for one to think that nothing remains in the urinary passage that he fears will exit later. And Allah the Almighty knows best.
Does burping (belching) break the fast?
Burping does not break the fast. However, if anything comes up from the stomach, the fasting person must spit it out and rinse their mouth to cleanse it.
If they swallow it intentionally while being able to expel it, or if they swallow their saliva before rinsing their mouth, their fast is invalidated.
Some online stores offer a discount on a customer's first purchase — what is the ruling on creating a new account each time a customer makes a purchase in order to obtain that discount?
All praise is due to Allah, and peace and blessings be upon our master the Messenger of Allah ﷺ.
It is obligatory upon a Muslim to uphold honesty in both his words and his actions. Allah the Almighty says {what means}: "O you who have believed, do not betray Allah and the Messenger or betray your trusts while you know." [Al-Anfāl/ 27] And He says {what means}: "O you who have believed, fear Allah and be with the truthful." [Al-Tawbah/ 119]. And the Messenger of Allah ﷺ said: "Whoever deceives us is not of us." (Reported by al-Bukhārī.)
As for creating a new account for the same buyer, the terms and conditions of the website must be observed and respected. If doing so violates those terms, it is not permissible. And Allah the Almighty knows best.
Is ablution invalidated when blood comes out of the nose, or a wound?
Blood coming out of the nose, or a wound does not invalidate ablution, but it is preferable to make ablution as a way out of the scholars disagreement in this regard.