Joshua pronounced a curse on anyone who rose up to rebuild Jericho Joshua 6:26. He said the builder would lay its foundation at the cost of his firstborn and set up its gates at the cost of his youngest son Joshua 6:26.
After Jericho’s fall, Joshua publicly binds the people with a sworn warning: anyone who tries to rebuild Jericho will come under a curse before Joshua 6:26. The curse is described as the loss of the rebuilder’s oldest son at the city’s foundation and the loss of the youngest when its gates are set up. These verses close the Jericho episode (Joshua 6), following the city’s collapse, the rescue of Rahab’s household, and the burning of the city. The oath functions like a concluding safeguard: Jericho is not just defeated; it is marked off as a place that should not be restored as a functioning fortified city.
Joshua 6:26–27 closes the Jericho account with two linked claims: a public oath warning against rebuilding Jericho, and a narrator’s note that Yahweh remained with Joshua and his reputation spread (Joshua 6:26; Joshua 6:27). The warning is framed “before Yahweh,” giving it religious weight and presenting the curse as more than a private opinion.
A careful answer keeps the immediate passage, the book's argument, and the whole-Bible storyline together, so the question is answered in context instead of as a detached idea.
Start with Joshua 6:26, then read the surrounding section so the answer stays connected to the passage's flow.
26Joshua charged them with an oath at that time, saying, Cursed be the man before Yahweh, that rises up and builds this city Jericho: with the loss of his firstborn shall he lay the foundation of it, and with the loss of his youngest son shall he set up the gates of it.