Why do muslims use Jesus" quotes?

I saw louis ferrakhan use a quote jesus used pertaining to what makes a man unclean. Jesus said what a man thinks from his heart makes him unclean. Ferrakhan used this verse in reference to the food you eat. He used a horrible ogy by claiming if you eat garbage you think garbage. Yet he skipped a simple verse that jesus spoke which said it is not what a man eats that makes him unclean. Would it be fair to say that in terms of christ and the truth muslims are completely clueless? Since mr ferrakhan is a highly respected figure in the islam world and sounds very unintelligent, what do you think about the rest of muslims?