The days of Noah! Genesis 6. The interpretation most common is the sons of Seth but I don’t buy it a bit. This interpretation lesser known but never condemned explains this whole theory
No, the "Sons of Seth" explanation is nonsense. Book of Enoch actually explains in great detail who these were. So, part of the problem has been, if these were fallen angels, since angels are pure spirit, how can they lust after human females and then assume bodies to mate with them?
So, I posit an intermediate type of angel, a missing link, as it were, in God's hierarchy of creation. In addition to angel, human, animal ... between human and angel you have the lowest tier of angel who, like humans, have a "sensible part" of their soul, but unlike humans, do not require having bodies of their essence, but where they can assume bodies ... not just animate them like puppets or possess them, but where they can fashion bodies for themselves out of inert matter, or earth, as they will, and have these bodies interface from that sensible part of their soul into the material world. Technically speaking, PURE spirits should not be able to interact with the material world. We have the example of those men who visited Abraham and ate with him ... but they ended up being angels. How do angels eat? Just a trick or an illusion? Did they find a few humans to possess? Pure angels, even if they assumed bodies, could not actually taste the food they were going wrong, since they would have no sensible part of their souls to which the density information could be common to their spirit.