"And if they do not respond to you"—meaning, by bringing ten surahs like it, and they will never do so—"then know that it was sent down with the knowledge of Allah"—that is, from the presence of Allah.
Surah Hud from verse (15) to verse (16).
﴿فَإِن لم يَسْتَجِيبُوا لكم﴾ فَيَأْتُوا بِعَشْرِ سورٍ مِثْلِهِ، وَلَنْ يَفْعَلُوا ﴿فَاعْلَمُوا أَنَّمَا أُنْزِلِ بِعِلْمِ الله﴾ أَي: من عِنْد الله.
سُورَة هود من الْآيَة (١٥) إِلَى الْآيَة (١٦).
