There's a hadith saying:
- "The Messenger of Allah said: 'Whoever conceals knowledge which Allah has made beneficial for mankind's affairs of religion, Allah will bridle him with reins of fire on the Day of Resurrection."
(Sunan ibn Majah -qualified as da'if by Darussalam)
- The Prophet said: "There is no man who memorizes knowledge then conceals it, but he will be brought forth on the Day of Resurrection bridled with reins of fire." (Hasan) Another chain with similar wording. (Sunan ibn Majah)
- Messenger of Allah (ﷺ) said: "Whoever is asked about some knowledge that he knows, then he conceals it, he will be bridled with bridle of fire."
(Jami' at-Tirmidhi qualified as Hassan by Darussalam)
How can we interpret this hadith?
Is it sinful to keep knowledge for oneself and hide it, if so under what circumstances or knowledge of what kind one shouldn't hide?