[2:159] Those who conceal the clear proofs and the guidance that We have revealed after We have shown them clearly in the Scripture - they shall be cursed by God and by the cursers,
The allusion in this verse is to those to whom the Real (s) has unveiled knowledge of the good manners of travelling and who have become stingy in revealing [this knowledge] to aspirants for the purposes of advice and guidance. In that moment they become loathsome. What is to be feared for them is that the blessing will be removed from their knowledge when they fall short in it, just as when they hold back in imparting it to the deserving.