We had said to you: "Your Lord has encompassed the people." We did not make the vision that We showed you except as a test for the people, and the tree that was cursed in the Quran. We alert them, but it only increases their transgression.
Translation endnotes
[17:60] This might be a reference to Muhammed's journey to receive revelation (17:1 and 53:1-18). The diabolically poisonous tree, zaqqum, grows inside hell (37:62-66) and we are informed that it will confuse and expose the hypocrites as unappreciative people since they cannot understand that the hellfire is a metaphor. With their shallow literal understanding, they solidify their dogmatic fanaticism by scoffing at the Quran, "How can a tree grow in the middle of fire?" God uses examples with multiple purposes, thereby guiding those who are appreciative and misleading those who have already made their minds and chosen the wrong path (2:26; 3:7; 17:82; 74:31). No wonder, the Quran is a mercy and reminder for those who wish to take heed (6:157; 7:203; 12:111; 17:82; 29:51; 31:3; 45:20).