Quran 70:34 from Surah Al-Ma'aarij on Divine Marvels.
وَٱلَّذِينَ هُمۡ عَلَىٰ صَلَاتِهِمۡ يُحَافِظُونَ
English translation: And those who [they] on their prayer keep a guard
Transliteration: wa-alladhina hum ala salatihim yuhafizuna