Abu Huraira reported: The Messenger of Allah, peace and blessings be upon him, said:
مَنْ سُئِلَ عَنْ عِلْمٍ عَلِمَهُ ثُمَّ كَتَمَهُ أُلْجِمَ يَوْمَ الْقِيَامَةِ بِلِجَامٍ مِنْ نَارٍ
Whoever is asked for knowledge and he conceals it, Allah will clothe him with a bridle of fire on the Day of Resurrection.
Source: Sunan al-Tirmidhī 2649, Grade: Sahih
