It is narrated from Sayyiduna Mu'awiyah (may Allah be pleased with him) that the Prophet (peace and blessings be upon him) forbade "ghulutat".
Ishaq narrates: Rawh bin Ubadah informed me from al-Awza'i that he said: "Ghulutat means difficult and complicated questions (asked to make someone err)."
Hadith Referenceالمعجم الكبير للطبراني / باب الميم / 16941