The Prophet ﷺ said: He who is two-faced in this world will have two tongues of fire on the Day of Resurrection. (Using translation from Abū Dāʾūd 4873)
قَالَ رَسُولُ اللَّهِ ﷺ «مَا كَانَ لَهُ وَجْهَانِ فِي الدُّنْيَا كَانَ لَهُ يَوْمَ الْقِيَامَةِ لِسَانَانِ مِنْ نَارٍ»