Surah Al-A'raf (The Heights), Verse 187

یَسْـَٔلُوْنَكَ عَنِ السَّاعَةِ اَیَّانَ مُرْسٰىهَا قُلْ اِنَّمَا عِلْمُهَا عِنْدَ رَبِّیْ لَا یُجَلِّیْهَا لِوَقْتِهَاۤ اِلَّا هُوَ ثَقُلَتْ فِی السَّمٰوٰتِ وَالْاَرْضِ لَا تَاْتِیْكُمْ اِلَّا بَغْتَةً یَسْـَٔلُوْنَكَ كَاَنَّكَ حَفِیٌّ عَنْهَا قُلْ اِنَّمَا عِلْمُهَا عِنْدَ اللّٰهِ وَلٰكِنَّ اَكْثَرَ النَّاسِ لَا یَعْلَمُوْنَ ۟

Yas'aloonaka 'anis Saa'ati aiyaana mursaahaa qul innamaa 'ilmuhaa 'inda Rabbee laa yujalleehaa liwaqtihaaa illaa Hoo; saqulat fis samaawaati wal ard; laa ta'teekum illaa baghtah; yas'aloonaka ka annaka hafiyyun 'anhaa qul innamaa 'ilmuhaa 'indal laahi wa laakinna aksaran naasi laa ya'lamoon

“They ask thee about the (final) Hour - when will be its appointed time? Say: "The knowledge thereof is with my Lord (alone): None but He can reveal as to when it will occur. Heavy were its burden through the heavens and the earth. Only, all of a sudden will it come to you." They ask thee as if thou Wert eager in search thereof: Say: "The knowledge thereof is with Allah (alone), but most men know not."”

Quran 7:187 (Yusuf Ali Translation)