Sahih Bukhari | Volume 5 | Hadith Number 228

Narrated by Ibn 'Abbas
Regarding the Statement of Allah:

And We granted the vision (Ascension to the heavens) which We made you see (as an actual eye witness) was only made as a trial for the people." (17:60)

Ibn Abbas added: The sights which Allah's Apostle was shown on the Night Journey when he was taken to Bait-ulMaqdis (i.e. Jerusalem) were actual sights, (not dreams).

And the Cursed Tree (mentioned) in the Qur'an is the tree of Zaqqum (itself).