"There is no denying its occurrence," meaning: it is not a lie.
Muhammad said: The meaning is: There is no occurrence of its occurrence that is a lie.
﴿لَيْسَ لوقعتها كَاذِبَة﴾ أَي: هِيَ كَاذِبَة.
قَالَ محمدٌ: الْمَعْنى: لَيْسَ لوقعتها وقْعَة كَاذِبَة.