The chapter
"There is none of you but will arrive at it, a matter decreed upon your Lord, inevitable." The verse stunned the companions until the next verse exhaled: "Then We will save those who feared Him, and leave the wrongdoers therein on their knees." The arrival is universal; the crossing is not.
The bridge is laid across the back of Jahannam: "and I and my ummah," he ﷺ said, "will be the first to cross." The engineering specifications, from Sahih Muslim: "slippery, seizing; on it hooks like the thorns of as-Sa'dan", a desert thorn every Arab listener knew by the scar: "except that none knows their size but Allah; they snatch the people by their deeds." Abu Sa'id added the description the Codex sets in this tile's metric: "It has reached me that the bridge is thinner than a hair and sharper than a sword."
The crossing moves by a law this world never knew: speed measured by deeds. "The believer crosses like the blink of an eye, like lightning, like wind, like birds, like the finest horses and riders, one delivered safe, one scratched and released, one shoved down into the Fire." Under a bridge lit by nothing, each crosser is issued his own illumination: "their light running before them and on their right", and the hypocrites, who borrowed light in the world, watch it switched off mid-span: "Wait for us that we may borrow from your light. It will be said: go back and seek light." A wall is struck between, mercy on its inner face, punishment on its outer.
On the span, the only sound the tradition reports from its greatest voices is a two-word du'a. The prophets themselves, the same men who split seas and cooled fires, stand at the bridge saying: "Allahumma sallim, sallim", O Allah, bring them through, bring them through. Whoever wants to know what the Day does to confidence: it reduces the messengers to two words, repeated.
And the scene the Sahihayn add to the crossing, which the Codex refuses to trim: the Qantara. After the bridge, the saved are halted on an arch before the Garden, and retribution is settled between them for the injustices that remained among believers, "until, when they are refined and purified, they are given leave to enter." The Garden's law at its gate: no unresolved wrong walks through. Forgive your brother tonight, the tile suggests, or the arch will settle it later.
The last man across is the tradition's most tender comedy: dragged, scorched, crawling, and then bargaining with his Lord tree by tree, oath after broken oath, until he is asked what would satisfy him and laughed toward more than he dreamed. He is the floor of the next node: the least citizen of a kingdom ten times this world.