The “gnostic” text called Asclepius could not appear more to be an actual Egyptian text, of what, about 1400 B.C.? at least on first reading. This beautiful section is a parable of manifold application, true in itself regardless of the source of the saying (Nag Hammadi Library in English, p. 300-301, translated by Brashler, etc.).
Therefore the mystery of intercourse is performed in secret, in order that the two sexes might not disgrace themselves in front of many who do not experience that reality. For each of them contributes its (own part in) begetting. For if it happens in the presence of those who do not understand the reality, it is laughable and unbelievable And, moreover, they are holy mysteries of both words and deeds, because not only are they heard, but they also are not seen.
…Therefore wickedness remains among the many, since learning regarding the things which are ordained …