ثُمَّ كَلَّا سَيَعْلَمُونَ
Then, no! They are going to know.
অতঃপর না, সত্বর তারা জানতে পারবে।
The best of you are those who learn the Quran and teach it.(Sahih al-Bukhari 5027)
Verse 5 of Surah An-Naba. This Surah is Meccan and has 40 ayahs; this ayah is in Juz 30.
Sahih International · মুহিউদ্দীন খান — Sources