Rabbi Adin Steinsaltz:
The fact that a man can create an angel, which is instantaneously transposed to another world, is not, in itself, a supernatural event.
It is a part of a day-to-day way of life that can on occasion seem ordinary and commonplace—the life of mitzvot.
When we perform an action that results in the creation of an angel, we are generally aware of no more than that we are acting on, and within, the physical world.
Similarly, the appearance of an angel does not necessarily involve a deviation from the normal laws of physical nature.
Man is thus in close contact with the upper worlds, and though the actual route, the nature of the link, is hidden, the fact of the relationship is as axiomatic as the duality of his body and soul, of matter and spirit.
Man does not pause to wonder every time he moves from the physical to the spiritual part of the World of Action, and takes for granted the occasional penetration of higher worlds into our world.
When we use the word “natural” in its widest possible meaning, that is, comprehending everything that we experience and know, the appearance and creation of angels are not “supernatural” phenomena.
Rabbi Adin Steinsaltz in The Strife of the Spirit, “Worlds, Angels, and Men”