Vowing to perform Hajj on behalf of the cousin who died on a journey

Q: My cousin was my colleague at school. We once went on a school trip. When he went to swim, he drowned. I made a vow to perform Hajj on his behalf. However, I have not performed Hajj until now. Do I have to perform Hajj on his behalf? When should I do so?

A: If the situation is as you have mentioned, you should fulfill your vow if you can, provided that you perform Hajj yourself first, according to Allah's saying, They (are those who) fulfil (their) vows, and they fear a Day whose evil will be wide-spreading. And the saying of the Prophet (peace be upon him), A person who vows to obey Allah should do so. May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.