If the sacrificial animal develops a defect after buying
If a person buys an animal for sacrifice and after that the animal develops such a defect that sacrifice of that animal will not be correct. The Shariah describes 2 cases about this:
1. If the person is wealthy and is performing a Compulsory (Wajib) sacrifice, then that person should not slaughter this animal but should buy another animal and sacrifice it.
2. If that person is not affluent and is performing a supererogatory (Nafl) sacrifice, then as that animal has already been selected, the person should sacrifice the same animal even though some defect might have developed in the animal later.
As mentioned in Durre Mukhtaar:
(Durre Mukhtaar, Vol. 5, Pg No. 229)
It is also mentioned in Radd Ul Muhtaar:
(Radd Ul Muhtaar, Vol. 5, Pg. No. 229)