It is slippery on which there are clamps and (hooks like) thorns which are wide at one side and narrow at the other and have bent ends.
A plant with such thorns is found in Najd and is called al-Sa’daan.
1, Some of the believers will cross as quickly as the wink of an eye,
2, Some others as quick as lightning,
3, like a strong wind,
4, or fast horses
5, or she-camels
6, So some will be safe without any harm;
7, some will be safe after receiving some scratches,
8, and some will fall down into Hell (Fire)
9, The last person will cross by being dragged
It is narrower than a hair and sharper than a sword.