مَنْ كَانَ ذَا وَجْهَيْنِ فِي الدُّنْيَا، كَانَ لَهُ يَوْمَ الْقِيَامَةِ لِسَانَانِ مِنْ نَارٍ
Translation: Whoever is two-faced in this world will have two tongues of fire on the Day of Resurrection.
Source: الدارمي
The literal sense of ذَا وَجْهَيْنِ is “possessing two faces”; it refers to someone who deceives different people by adopting contradictory positions to please or manipulate them. كَانَ describes the first condition, while كَانَ لَهُ introduces its consequence. لِسَانَانِ is dual: two tongues.
The warning targets deliberate duplicity, not every variation in manner or expression. Speaking appropriately to different audiences, protecting a confidence, or mediating respectfully does not automatically amount to the condemned conduct.