Indeed, We made it (the Zaqqum tree – the body) an object of trial (to see if they will remember their essence or if they will live as though they are the body).
Sayyed Abbas Sadr-Ameli
Verily We have appointed it as a trial for the unjust.
Al-muntakhab fi tafsir al-Qur'an al-Karim
The tree We caused to grow especially for the trial in sharp tribulation and misery of the wrongful of actions