- Prajapati said to Himself: "Well, let Me make a firm basis for it (semen)." So He created woman. Having created her, He placed her below and worshipped her. Therefore one should worship a woman, placing her below. He (Prajapati) extended His organ that projects and with it impregnated her. (Verse 6.4.2) brihadaranyaka upanishad Chapter IV—Conception and Birth as Religious Rites Verse
He was not at all happy. Therefore people (still) are not happy when alone. He desired a mate. He became as big as man and wife embracing each other. He parted this very body into two. From that came husband and wife. Therefore, said Yājñavalkya, this (body) is one-half of oneself, like one of the two halves of a split pea. Therefore this space is indeed filled by the wife. He was united with her. From that men were born.(verse1.4.3)Bṛhadāraṇyaka Upaniṣad Chapter I > Section IV - The Creation and Its Cause
In the first verse Prajapati created the woman but in the second verse (1.4.3) aham split himself into two man and a woman.
Why there is a contradiction between these two verses