مَنْ سُئِلَ عَنْ عِلْمٍ عَلِمَهُ، ثُمَّ كَتَمَهُ، أُلْجِمَ يَوْمَ الْقِيَامَةِ بِلِجَامٍ مِنْ نَارٍ
Translation: Whoever is asked about knowledge they possess and then conceals it will be bridled with a bridle of fire on the Day of Resurrection.
Source: أحمد والترمذي
سُئِلَ is passive: “was asked.” عَلِمَهُ indicates knowledge the person really possesses. ثُمَّ كَتَمَهُ means “then concealed it.” The response أُلْجِمَ is also passive: “will be bridled,” a severe warning.
Knowledge is a trust. When a person genuinely knows the answer to a matter and guidance is appropriately needed, withholding it out of arrogance, resentment, or self-interest is blameworthy. Responsible teaching also requires accuracy, awareness of the learner’s needs, and respect for the limits of one’s competence.