What is the evidence for the validity of Hajj performed with ill-gotten gains, and does this contradict the Prophet's saying, "Indeed, Allah is good and accepts only what is good"?

The majority of scholars hold that one who performs Hajj with unlawfully acquired money has a valid and sufficient Hajj, though he is sinful for committing a forbidden act, which is consuming unlawful wealth. Their evidence is that Hajj consists of specific actions, and the prohibition is due to a meaning external to these actions; that is, the command to perform Hajj is separate from the prohibition against consuming unlawful wealth. As for Imam Ahmad, he is of the view that Hajj is not sufficient in this case.