Quran 23:2 from Surah Al-Muminoon on Divine Marvels.
ٱلَّذِينَ هُمۡ فِي صَلَاتِهِمۡ خَٰشِعُونَ
English translation: Those who [they] during their prayers (are) humbly submissive
Transliteration: alladhina hum fi salatihim khashi'una