What is the Sirat bridge?

What the hadith say

The word "sirat" means path. In the hadith, the Prophet ﷺ described a bridge laid across hell after the judgement. He said he and his ummah would be the first to cross it, that on that day only the messengers would speak, and that their words would be "O Allah, keep us safe, keep us safe" (Sahih al-Bukhari 806). Along the bridge there are hooks, like the thorns of a desert plant, that snatch people according to their deeds.

The Companion Abu Sa'id al-Khudri added that the bridge is "thinner than a hair and sharper than a sword" (Sahih Muslim 183). Scholars say we believe in this as described, without trying to picture exactly how it works, since it belongs to the unseen.

Many scholars explain this verse as referring to passing over the Sirat. The next verse says Allah then saves those who were mindful of Him (Quran 19:72).

Different speeds for different people

The Prophet ﷺ said people will cross like the blink of an eye, like lightning, like the wind, like birds, and like fast horses, carried by their deeds. Some will crawl, and some will be dragged into the Fire. He also said that trust (amanah) and family ties will stand on both sides of the bridge (Sahih Muslim 195). In other words, how honest you were and how you treated your relatives matter on that day.

Light on the bridge

The Quran describes believers on that day with light running ahead of them and on their right (Quran 57:12). Their light will be in proportion to their faith and deeds. Hypocrites will ask for some of it and will not find it.

Once across, believers reach the gates of Paradise. See What is Jannah? and What are the levels of Jannah?