Q: *Is it permissible to purchase a share of the Qurbani for a deceased relative?
A: *If you have taken a share for yourself, then it is permissible for you to offer qurbani in the name of a deceased person. Because qurbani is wajib on a living rich adult muslim whether male or female. But not wajib on deceased unless, he instructed to do qurbani before he left this world.
If doing isaale sawaab, then permissible to include lots of deceased names in that one share.(Fatawa Zakarya) But if doing a qurbani on the instruction of the deceased, then should include only one name in that share.
* *If doing isaale sawaab, then the payer of the share may keep the meat or distribute it. 6 persons taking share in a bull or cow may take the 7th share as a collective isaale sawaab on their respective intentions. The 7th share will be divided into 6 parts.
But if doing a qurbani instructed by the deceased, then the meat should be given to the poor in sadaqah. Ahadith on the subject:
A hadith of Abu Dawood and retaken by Mustadrak Hakim shows that hazrat Ali r.a. used to perform the qurbani two sheep. The first sheep was named on behalf of Nabi SAW and then the second one for himself:فمنها ما حدثنا الشيخ أبو بكر بن إسحاق ، أنبأ بشر بن موسى الأسدي ، وعلي بن عبد العزيز البغوي ، قالا : ثنا محمد بن سعيد بن الأصبهاني ، ثنا شريك ، عن أبي الحسناء ، عن الحكم ، عن حنش ، قال : ضحى علي ، رضي الله عنه بكبشين كبش عن النبي صلى الله عليه وسلم
وكبش عن نفسه وقال : « أمرني رسول الله صلى الله عليه وسلم أن أضحي عنه » فأنا أضحي أبدا « هذا حديث صحيح الإسناد ولم يخرجاه ، وأبو الحسناء هذا هو : الحسن بن الحكم النخعي »
And also reported in Tirmizi that the beloved prophet Swalallahou `Alaihi Wasallam did Qurbani in sawaab for his Ummah. Some of the Ummah were not yet born.* *Hence, Qurbani done to please Allah Ta`ala done in favour of deceased permissible. But know that qurbani is wajib on all living adult muslim that are rich. And wajib on them each year.