Anas reported God's messenger as saying, "There is no prophet who has not warned his people about the one-eyed liar. I tell you that he is one-eyed, but your Lord is not one-eyed. On his forehead are the letters k, f, r." * *Meaning kufr (infidelity) to which he summons people. (Bukhari and Muslim.)
Hadith Referenceمشكوة المصابيح / كتاب الفتن / 5471
Hadith Gradingالألبانی:مُتَّفَقٌ عَلَيْهِ | زبیر علی زئی:متفق عليه
Hadith Takhrij´تحقيق و تخريج: محدث العصر حافظ زبير على زئي رحمه الله` «متفق عليه، رواه البخاري (7131) و مسلم (101 / 2933)»