Midrash sobre Gênesis 2:28

The Holy One, blessed be He, had compassion upon the first man (Adam), and, in order that he should not feel any pain, He cast upon him the sleep of deep slumber, and He made him sleep whilst He took one of his bones from his side and flesh from his heart and made it into an help (meet for him) and placed her opposite to him. When he awoke from his sleep he saw her standing opposite to him. And he said, "Bone of my bones and flesh of my flesh" (Gen. 2:28). As long as he was alone he was called Adam (man).