هل تُصبح الأضحية التي تبرَّعَ بها شخصٌ ما أُضحيةً بالنسبة لهم؟

There are two scenarios for someone donating an Udhiyah (sacrifice) on behalf of another:

The first: On behalf of a deceased person. This is permissible according to the majority of scholars, and according to one opinion among the Shafi'is. Another opinion among the Shafi'is holds that it is not valid unless the deceased person bequeathed it.

The second: On behalf of a living person. This is not permissible except with their permission. This is the view of most scholars, because it is an act of worship.