﴿ وَلَتَعْلَمُنَّ نَبَأَهُۥ بَعْدَ حِينٍۭ ﴾

“and you will most certainly grasp its purport after a lapse of time!””

And you will assuredly come to know O disbelievers of Mecca its tiding the news of its truth in due time’ that is to say on the Day of Resurrection ‘ilm ‘knowing’ is here being used in the sense of ‘urf ‘experience’; the prefixed lām in la-ta‘lamunna ‘you will assuredly know’ is for an implicit oath in other words what is meant is wa’Llāhi la-ta‘lamunna ‘By God you will assuredly know’.