The angels are witness to it:

Perform As-Ṣalāt(Iqāmat-Al-Ṣalāt) (prayer) from mid-day till the darkness of the night (i.e. the Ẓuhr, 'Aṣr, Maghrib, and 'Ishā prayers), and recite the Qurān in the early dawn (i.e. the morning prayer). Verily, recitation of the Qurān in the early dawn is ever witnessed (attended by the angels in charge of mankind of the day and the night). [Al Isrā: 78]