In Genesis 6 "sons of God" is a term that is usually interpreted to mean angels. Cabalistically they are an order of angels (the bene elohim) who belong to the eighth Sephira (Hod) of the Tree of Life. It is also said that, as Watchers, they never sleep. The same is also said of the Irin.

The Book of Jubilees states that the Watchers are the sons of God from Genesis 6 who were sent to earth to teach human children. When they descended to earth they cohabitated with human women, thus condemning themselves and becomng fallen angels. Not all of the Grigori descended to earth, however, and those who remained in heaven are the holy Watchers who live in the Fifth Heaven. Those that did fall live in either the Third Heaven or in Hell.

In The Zohar, however, Simeon ben Yohai, the book's author, cursed anyone, especially his disciples, who interpreted Genesis 6 to mean that the sons of God were equipped with the sexual organs necessary for them to have had fornicated with mortal women, for angels are said to be asexual. In fact, according to Enoch I, there were seven watchers who fell, not because they fornicated with moral women, but because they were late in reporting to their assigned tasks.

Nefillim are the giant offspring of the unions between fallen angels and human women. The Zohar says that they were so tall "the Hebrews were like grasshoppers in comparison." It also singles out Uzza and Azael for having had children "whom they called anakim." In Ginzberg's The Legends of the Jews it says that the anakim "touched the sun with their necks." The view that the angels reached from Heaven to earth just as Adam and Israfel did when they were created is often expressed in rabbinic and Islamic texts. It is still said that Israfel still does.