Surah Al-Jum'ah (The Friday Congregation), Verse 9

یٰۤاَیُّهَا الَّذِیْنَ اٰمَنُوْۤا اِذَا نُوْدِیَ لِلصَّلٰوةِ مِنْ یَّوْمِ الْجُمُعَةِ فَاسْعَوْا اِلٰی ذِكْرِ اللّٰهِ وَذَرُوا الْبَیْعَ ذٰلِكُمْ خَیْرٌ لَّكُمْ اِنْ كُنْتُمْ تَعْلَمُوْنَ ۟

Yaaa ayyuhal lazeena aamanoo izaa noodiya lis-Salaati miny yawmil Jumu'ati fas'aw ilaa zikril laahi wa zarul bai'; zaalikum khayrul lakum in kuntum ta'lamoon

“O ye who believe! When the call is proclaimed to prayer on Friday (the Day of Assembly), hasten earnestly to the Remembrance of Allah, and leave off business (and traffic): That is best for you if ye but knew!”

Quran 62:9 (Yusuf Ali Translation)