The Messenger of Allah ﷺ said, "Whoever is two-faced in this world will have two tongues of fire on the Day of Resurrection."
قال رسول الله ﷺ: من كان له وجهان في الدنيا، كان له يوم القيامة لسانان من نار.
Abu Dawud (4873) narrated it, as did Bukhari in Adab al-Mufrad (1310) and Abu Yaala (1620), and Ibn Hibban graded it sahih (5756). All of them narrated it through the route of Sharik, from Rukayn bin Rabi, from Nuaym bin Hanzala, from Ammar, and he mentioned it. Its isnad is hasan, because of Sharik, who is Ibn Abdullah, the judge of Nakhaa, who had weak memory, while Nuaym bin Hanzala was deemed trustworthy by Ajli, and Ibn Hibban mentioned him among the trustworthy narrators. Ali bin Madini said, "Its isnad is hasan, and we do not know of it being narrated from Ammar, from the Prophet ﷺ, except through this route." Mizzi mentioned this in his Tahdheeb, in the biography of Nuaym bin Hanzala.I say, Ali bin Madini's grading of it as hasan indicates that Sharik bin Abdullah, despite having weak memory, got this hadith right, since there are corroborating narrations for it. Among them is what was narrated from Anas bin Malik, that the Messenger of Allah ﷺ said, "Whoever has two tongues in this world, Allah will give him two tongues of fire." This was narrated by Abu Yaala (2771, 2772), Hannad in Zuhd (1137), and Bazzar in Kashf Astar (2025), all of them through the route of Ismail bin Muslim Makki, from Hasan and Qatada, from Anas, and he mentioned it, the wording given here being Abu Yaala's.Bazzar said, "We do not know of it being narrated from Hasan, from Anas, except by Ismail, who transmitted it alone from Anas." I say, it is not as he said, for Tabarani narrated it in Awsat (8880) from Miqdam, who said, Asad narrated to us, who said, Ayub bin Khawt narrated to us, who said, Qatada narrated to us, from Anas, and he mentioned something similar. Tabarani said, "This hadith was not narrated from Ayub except by Asad, and it was not narrated from Qatada except by Ayub and Ismail bin Muslim."Haythami said in Majma (8/95), "Tabarani narrated it in Awsat, and among its narrators is Miqdam bin Dawud, who is daif. Bazzar narrated something similar, as did Abu Yaala, and among its narrators is Ismail bin Muslim Makki, who is daif."Similar in meaning is what was narrated from Saad bin Abu Waqqas, Jundab bin Abdullah Bajali, Abu Hurairah, and others, all of which are flawed. The one I have mentioned is the soundest of them.