Genesis 8: 11: And the dove came in to him in the evening; and, lo, in her mouth was an olive leaf pluckt off: so Noah knew that the waters were abated from off the earth.
When the waters of the Flood were receding from the earth, Noah sent forth a dove to see if dry land was sticking past the waterline. When the dove returned to the Ark with an olive leaf in her mouth, then Noah knew that the water level was indeed getting lower and dry land was becoming visible.
The dove represents the Holy Spirit coming to the prophet Noah, bringing information (the olive leaf) about the new world he and his family would enter into. So in these last days the Dove of the Holy Spirit came to our prophet bringing information (tremendous revelations) about the new world we will enter into.