There have been many misreading of Matthew 19 that have been brought on by people of secular epistemology. Whether it is stating that Christ refers to a homosexual in this context or that (Most recently) there is room for a gray area between genders/sexes. This is very important text and it's one that should be looked at with careful eyes through a well-established hermeneutic. You'll see quickly that it has nothing to do with gender, sex or any philosophical social construct.
Scripture:
1 Now when Jesus had finished these sayings, he went away from Galilee and entered the region of Judea beyond the Jordan. 2 And large crowds followed him, and he healed them there. 3 And Pharisees came up to him and tested him by asking, “Is it lawful to divorce one's wife for any cause?” 4 He answered, “Have you not read that he who created them from the beginning made them male and female, 5 and said, ‘Therefore a man shall leave his father and his mother and hold fast to his wife, and the two shall become one flesh’? 6 So they are no longer two but one flesh. What therefore God has joined together, let not man separate.” 7 They said to him, “Why then did Moses command one to give a certificate of divorce and to send her away?” 8 He said to them, “Because of your hardness of heart Moses allowed you to divorce your wives, but from the beginning it was not so. 9 And I say to you: whoever divorces his wife, except for sexual immorality, and marries another, commits adultery.”[a] 10 The disciples said to him, “If such is the case of a man with his wife, it is better not to marry.” 11 But he said to them, “Not everyone can receive this saying, but only those to whom it is given. 12 For there are eunuchs who have been so from birth, and there are eunuchs who have been made eunuchs by men, and there are eunuchs who have made themselves eunuchs for the sake of the kingdom of heaven. Let the one who is able to receive this receive it.”
Commentary:
Jesus is responding to His disciples here in regards to those who have questions about the morality of marriage and what would constitute for a divorce certificate. It must be noted that takes place this within the confines of the current Jewish Culture, which is why in a moment you'll see Jesus refer to 3 types of Eunuchs. The category that is being spoken of is MARRIAGE; let's keep that in our focus.
Followers of Hillel felt a man could divorce his wife for almost any reason, but others, following Shammai, thought one could not divorce his wife unless she were guilty of sexual offense. Without getting involved in the Hillel-Shammai controversy Jesus reminded the religious leaders of God’s original purpose in establishing the marriage bond. God made people male and female (v. 4; Gen. 1:27) Christ's answer was that Moses granted this permission because people’s hearts were hard (cf. Deut. 24:1-4). “Because your hearts were hard” is literally, “toward your hardness of heart” But that was not God’s intention for marriage. God intended husbands and wives to live together permanently. Divorce was wrong except for marital unfaithfulness (cf. Matt. 5:32).
Verse 3: This was a question of dispute between the rival Rabbinical schools of Hillel and Shammai; the former asserting the right of arbitrary divorce, from Deuteronomy 24:1, the other denying it except in case of adultery.
for every cause;—i.e. is any charge which a man may choose to bring against his wife to justify him in divorcingher? [γυναικὸς τῆς συνοικούσης βουλόμενος διαζευχθῆναι καθʼ ἃς δηποτοῦν αἰτίας,— πολλαὶ δʼ ἂν τοῖς ἀνθρώποις τοιαῦται γίνοιντο,— γράμμασι μὲν περὶ τοῦ μηδέποτε συνελθεῖν ἰσχυριζέσθω]
Verse 5: Stier remarks, that the essential bond of marriage consists not in unity of spirit and soul, by which indeed the marriage state should ever be hallowed and sweetened, but without which it still exists in all its binding power:—the wedded pair are ONE FLESH, i.e. ONE MAN within the limits of their united life in the flesh, for this world: beyond this limit, the marriage is broken by the death of the flesh. And herein alone lies the justification of a second marriage, which in no way breaks off the unity of love in spirit with the former partner, now deceased. Vol. ii. p. 267, edn. 2.
In this second question, the Pharisees imagine that they have overthrown our Lord’s decision by a permission of the law, which they call a command. But He answers them that this was done by Moses on account of their hardness and sinfulness, as a lesser of evils, and belonged to that dispensation which παρεισῆλθεν, Romans 5:20; τῶν παραβάσεων χάριν προσετέθη, Galatians 3:19. He is guiding them through what the Law states and why the law isn't being overthrown.
Now onto the bedrock of this Scripture which is where the obviously misuse comes in. I want to be very critical, analytical and thoughtful here. Jesus mentions the three exceptions {with the same word of Eunuch}, the οἷς δέδοται οὐ γαμῆσαι. 1. Those who from natural incapacity, or if not that, ineptitude, have no inclination for marriage (Jewish Culture nearly prohibited men to marry who could not procreate because children were seen as blessing from God) 2. Those who by actual physical deprivation, or see Royal Servanthood, are prevented from marrying: 3. Those who in order to do the work of God more effectually (as e.g. Paul), abstain or refrain from marriage, see 1 Corinthians 7:26. The εὐνοῦχοι and εὐνουχίζω in the two first cases are to be taken both literally and figuratively in the latter, figuratively only. It is to be observed that Jesus does not here utter a word from which any superiority can be attributed to the state of celibacy: the imperative in the last clause being not a command but a permission, as in Revelation 22:17. His estimate for us of the expediency of celibacy, as a general question, is to be gathered from the parable of the talents, where He visits with severe blame the burying of the talent for its safer custody.
Finally, verse 12 states "Not all men will receive this, only those whom it is given". Therefore, we can deduce that this Scripture is highly important for the sake of understanding the cause of divorce but also the relationship of marriage's origin. The categories of the three eunuchs mentioned all fall under the realm of marriage and NOT social constructs of gender, sex or anything that is a byproduct of that.