[19] i.e., out of terror they will be on their knees or dragged unwillingly while on their knees.
[20] Referring to the bridge of As-Sirāt, which is placed over Hell. Everyone will pass on it. The believers will cross it easily, each according to their faith, whereas the disbelievers and the hypocrites will fall into the Fire from the bridge.
[21] In regard to the life of this world.