Narrated 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 Quran is the tree of Zaqqum (itself) .

حَدَّثَنَا الْحُمَيْدِيُّ، حَدَّثَنَا سُفْيَانُ، حَدَّثَنَا عَمْرٌو، عَنْ عِكْرِمَةَ، عَنِ ابْنِ عَبَّاسٍ ـ رضى الله عنهما ـ فِي قَوْلِهِ تَعَالَى {وَمَا جَعَلْنَا الرُّؤْيَا الَّتِي أَرَيْنَاكَ إِلاَّ فِتْنَةً لِلنَّاسِ} قَالَ هِيَ رُؤْيَا عَيْنٍ، أُرِيَهَا رَسُولُ اللَّهِ ﷺ لَيْلَةَ أُسْرِيَ بِهِ إِلَى بَيْتِ الْمَقْدِسِ. قَالَ وَالشَّجَرَةَ الْمَلْعُونَةَ فِي الْقُرْآنِ قَالَ هِيَ شَجَرَةُ الزَّقُّومِ.