Joshua 6:26

26 At that time Joshua pronounced this solemn oath: “Cursed before the LORD is the one who undertakes to rebuild this city, Jericho: “At the cost of his firstborn son he will lay its foundations; at the cost of his youngest he will set up its gates.”

Read Joshua 6:26 Using Other Translations

And Joshua adjured them at that time, saying, Cursed be the man before the LORD, that riseth up and buildeth this city Jericho: he shall lay the foundation thereof in his firstborn, and in his youngest son shall he set up the gates of it.
Joshua laid an oath on them at that time, saying, "Cursed before the LORD be the man who rises up and rebuilds this city, Jericho. "At the cost of his firstborn shall he lay its foundation, and at the cost of his youngest son shall he set up its gates."
At that time Joshua invoked this curse: “May the curse of the LORD fall on anyone who tries to rebuild the town of Jericho. At the cost of his firstborn son, he will lay its foundation. At the cost of his youngest son, he will set up its gates.”