Matthew 19:12

For 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.

The Jews of Christ's time had a very low view of women, and therefore of marriage. And the disciples were not free from the national ideas and prejudices. They had never had the subject presented to them like this before. If such be the state of affairs so far as the relations between husband and wife are concerned, they say, if the husband must regard his wife so highly, and if both husband and wife must regard the marriage bond as indissoluble, if this recourse to quick and easy divorces is both against the original order of God's institution and against His revealed will, then it is poor policy to get married. But Christ corrects their poor understanding, and shows distinctly that the estate of marriage is the normal state for normal adults, only such individuals being ordinarily exempt from this rule whose physical and spiritual condition renders them unfit for the duties peculiar to the physical side of marriage. Some people are naturally, from their birth, incapable of contracting marriage. Others have been rendered impotent, sterile, through deliberate mutilation by others, as was done in the case of the Oriental eunuchs. Still others purposely force themselves to chastity, to a life outside of marriage, keeping the natural desires in subjection, in order to be able to devote their entire time and life to the service of the kingdom of God. But all three classes are abnormal, even the last, except in cases of religious persecution or for some other extraordinary reason, 1 Corinthians 7:26. Herewith Christ neither commands nor recommends celibacy, but sets these people, as a class, in a separate category, and warns that it takes a great deal of spiritual and moral capacity to grasp His saying. The claims of the kingdom of heaven are paramount, but Christ expects no one to feign an asceticism to which he is not fully equal, since that would be setting aside the law for the propagation of the human race by the order of marriage, which Christ has, throughout His declaration, very warmly defended. See 1 Corinthians 9:5. The last state described by Christ may, under circumstances, be preferable to the married state, but it takes an exceptional spiritual enlightenment to grasp it.