This is from the midrash (ancient Jewish homily), Chapter 30, subchapter 80 in Bereishit Rabba. It makes a simple point, easy to teach to young impressionable children. I first learned it in Beis Yaakov:

Rabbi Joshua of Sichnin said in the name of Rabbi Levi..."So it is written, ‘And the Lord built the rib’ (Gen 2:22). When scripture says ‘he built’ (va'yiven), using the word that yields the meaning ‘he understood’ (va'yavin), the sense is that he gave considerable thought to the question of the place on man at which to begin to create woman. He thought to himself, 'We should not create her beginning with the head, so that she not be too frivolous, nor from the eye, that she not be a starer, nor from the ear, that she not be an eavesdropper, nor from the mouth, that she not talk too much, nor from the heart, that she not be jealous, nor from the hand, that she not be light-fingered, nor from the foot, that she not be a gadabout, but from a covered up place up on man (the rib). For even when a man is standing naked, that spot is covered up.' And as he created each part of the woman, he would say to her, 'Woman, modesty! Woman, modesty!'"