What is the ruling on supererogatory prayers before the the dawn (Fajr) call to prayer, what is their benefit, and are they considered part of Qiyam al-Layl (night vigil prayer)?

Performing supererogatory prayers (Nawafil) before the dawn breaks is considered part of the night vigil (Qiyam (definition) al-Layl). It is one of the best acts of drawing closer to Allah after the five obligatory prayers. It has tremendous benefits, including that it is the practice of the righteous, a means of drawing closer to Allah, a deterrent from sin, an expiation for misdeeds, and a ward against illness from the body.