It is narrated from Sayyiduna Thawban (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "Soon there will be people from my Ummah whose jurists will occupy themselves with intricate (and perplexing) questions; those are the worst of my Ummah."
Hadith Referenceالمعجم الكبير للطبراني / باب الثاء / 1418