What is the meaning of the recitation of dawn which is ever witnessed that is mentioned in [Quran 17:78]?

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.

The meaning of the Saying of Allaah (which means): {…the Quran [i.e. recitation] of dawn.} is the prayer of dawn. The evidence for this is: Abu Hurayrah narrated that the Prophet said: "The congregational prayer is better than the individual prayer by twenty five degrees, and the angels of the day and the those of the night gather at dawn prayer.” Then Abu Hurayrah added: “Read if you want [the Saying of Allaah (which means)]: {…the Quran [i.e. recitation] of dawn. Indeed, the recitation of dawn is ever witnessed.}[Quran 17:78]". [Al-Bukhari]

Allaah Knows best.