Going for Haj with Haraam Money

1. It comes in the Hadeeth that a person who makes Haj with haraam wealth and says, “Labbaik! Allahumma, Labbaik!” – This is the Du’aa which is recited when in Ihraam. It means: “I am present in Your service, O Allah! I am present in Your service” – then Allah Azza Wa Jall responds: “Laa Labbaik Wa Laa Sa’daik, wa Hajjuka mardoodun alaik!” (Your ‘labbaik’ is not accepted, and there is no good fortune for you! Your ‘haj’ is flung back in your face!)
2. In other words: You have not come out of Our obedience. If you came in obedience to Us, you would have spent halaal wealth and come. Your ‘haj’ is not accepted in Our Sublime and Holy Court. You will not get the desired thawaab for it (though the Fardh is discharged).

(Behshti Zewar)