“To play his part in the great restoration of all things, Gabriel came in modern times and conferred the keys of his dispensation upon Joseph Smith. As with other angelic ministrants to this earth, Gabriel also spent his mortal probation here. He is Noah, the one who stands next to Michael or Adam in the priesthood hierarchy. (Teachings, p. 157.)” Mormon Doctrine, 301.
“The Priesthood was first given to Adam…Then to Noah, who is Gabriel; he stands next in authority to Adam in the Priesthood; he was called of God to this office, and was the father of all living in his day, and to him was given the dominion. These men held keys first on earth, and then in heaven. (Joseph Smith, History of The Church of Jesus Christ of Latter-day Saints, 7 Vols. 3:385-86).” Encyclopedia of Joseph Smith’s Teachings, 446.
The Church has never hidden the teachings of Gabriel being Noah and vice versa. This is just another way the Church intentionally serves to confuse the members and keep their minds on things that aren’t true. In Gen. chapter six of the Bible, we find the story of righteous Noah and the wicked earth. No where in the Bible does it allude to any idea that he was Gabriel or that he came back to testify to Joseph Smith!
Gabriel on the other hand is mentioned by Daniel when he had his vision. See Daniel 8:16-9:21. And of course there was the visit of Gabriel to both Joseph and Mary to announce the coming birth of the Messiah in Luke 1:19 and 26.