4And he answered and said unto them, Have ye not read, that he which made them at the beginning made them male and female,
5And said, For this cause shall a man leave father and mother, and shall cleave to his wife: and they twain shall be one flesh?
6Wherefore they are no more twain, but one flesh. What therefore God hath joined together, let not man put asunder.
7They say unto him, Why did Moses then command to give a writing of divorcement, and to put her away?
8He saith unto them, Moses because of the hardness of your hearts suffered you to put away your wives: but from the beginning it was not so.
9And I say unto you, Whosoever shall put away his wife, except it be for fornication, and shall marry another, committeth adultery: and whoso marrieth her which is put away doth commit adultery.
10His disciples say unto him, If the case of the man be so with his wife, it is not good to marry.
11But he said unto them, All men cannot receive this saying, save they to whom it is given. 12For there are some eunuchs, which were so born from their mother's womb: and there are some eunuchs, which were made eunuchs of men: and there be eunuchs, which have made themselves eunuchs for the kingdom of heaven's sake. He that is able to receive it, let him receive it.
Natural and man-made eunuchs co-existed as distinct categories for at least a thousand years, from the first-reported mass castrations about 600 BCE until 400 CE." The willingness to engage in homosexual activity (particularly intergenerationally) was widespread among men in the ancient Mediterranean region. Women and boys were considered equally tempting sex objects for those whom we would call heterosexual men.
However, the ancients did differentiate based on an unwillingness or incapacity for heterosexual sex. Certain men were known to fundamentally lack arousal for sex with women, and men of this kind were distinguished from the majority of ordinary men on that basis. The innately and exclusively homosexual men of the ancient world inhabited the category of eunuchs. What we moderns think of as a eunuch, namely a castrated man, was simply an artificially manufactured homosexual.