Because of an additional letter that appears in the Torah in the Creation story, the Gemara offers a variety of explanations – one of them suggesting that in the original creation of Man the creation was androgynous.
Rabbi Yirmeya ben Elazar said: The Holy One, Blessed be He, created two faces on Adam the first man; he was created both male and female in a single body, as it is stated: “You have formed me [tzartani] behind and before” (Tehillim 139:5); tzartani is derived from the word tzura [face]. God formed two faces on a single creation, back and front.
In the Gemara in Ketubot (daf 8a), in the context of seeking to explain a dispute, the possibility is raised that there is a disagreement whether there was a single creation of Man or if there was a second Creation, as well. Most commentaries tie that dispute to the question in our Gemara, whether man was created with one face and the woman was subsequently an independent creation, or whether he was created with two faces and the creation of Eve was merely the separation the two faces from each other, i.e., not a creation at all. Another possible explanation of the dispute is based on the opinion in our Gemara: At first, the thought entered His mind to create two, but ultimately only one was created. On that basis, the dispute can be explained as a disagreement: Which is the determining factor, thought or action?
Our Gemara continues discussing the creation of Man
It is stated: “And the tzelah which the Lord, God, had taken from the man, He made a woman, and brought her unto the man” (Bereshit 2:22). Rav and Shmuel disagree over the meaning of the word tzelah: One said: It means face. Eve was originally one face or side of Adam. And one said: It means tail, which he explains to mean that the tzelah was an appendage, i.e., one of the ribs in Adam’s chest.
The Aruk explains that the word tail, here and in several other places in the Talmud, refers to an appendage that is unlike the object to which it is attached in appearance or size. The Rashba explains “tail” in this context as a limb of secondary importance, as a tail is to a body.