This is part of the bedtime Shema, the prayers and meditations before sleep, found in the Siddur after the evening service, Maariv.

One of the most ancient names of Gd is "El" and we see that name in the names of the angels.

The first angel is Michael "mi"="who" "C"="like" [is] like GD right side

The second angel is Gavriel the Gevurah, power of Gd left side

The third angel is Uriel the Or light of Gd in front

The fourth angel is Rafael healed by Gd following

The fifth angel is Shekhinat El the Shekhina feminine presence of Gd above the head.

The breathing sounds are reminders to take deep, full breaths as you do the meditation, through the nose, holding slightly as feels comfortable.

This meditation brings great protection and comfort, and can be used as a mantra anywhere, anytime.