44:43Ad-Dukhaan

“O you who believe! Have fear of Allah as is His due, and die not except as Muslims. (Then he said): ‘If a drop of Zaqqum were to be dropped on the earth, it would ruin the livelihood of the people of this world, so how about those who have no food other than it (i.e. Zaqqum)?’”

"There is not a tree in Paradise except that its tree is of gold."

(regarding the Verse) "And We granted the vision (Ascension to the heavens "Miraj") which We showed you (O Muhammad as an actual eye witness) but as a trial for mankind.' (17.60): Allah's Apostle actually saw with his own eyes the vision (all the things which were shown to him) on the night of his Night Journey to Jerusalem (and then to the heavens). The cursed tree which is mentioned in the Qur'an is the tree of Az-Zaqqum.

Regarding: 'And We granted the vision (Ascension to the Heaven "Miraj") which We showed you (O Muhammad as an actual eye witness) but as a trial for mankind.' (17.60) It was an actual eyewitness which was shown to Allah's Messenger (ﷺ) during the night he was taken on a journey (through the heavens). And the cursed tree is the tree of Az-Zaqqum (a bitter pungent tree which grows at the bottom of Hell).

"The Messenger of Allah (ﷺ) was brought a dish with unripe dates on it. He said: The parable of a goodly word is that of a goodly tree, whose root is firmly fixed, and its branches (reach) to the sky (14:24 & 25).' And he said: 'It is the date-palm.' And the parable of an evil tree uprooted from the surface of the earth, having no stability (14:26). He said: 'It is the colocynth tree.'"