The Pharisees test Jesus by asking about divorce. His answer has broad ranging applications. Jesus allows little children to be brought to him then tests the faith of a rich young man who believes he keeps the entire Law. Look for a couple of very well known quotes from Jesus in this chapter.
Matthew 19
When Jesus had finished these sayings, he departed from Galilee and came into the coasts of Judea beyond Jordan;
2 Large crowds followed him and he healed them there.
3 The Pharisees also came to him, testing him saying “Is it lawful for a man to put away his wife for any cause?”
4 And he answered and said to them “Have you not read, that he which made them in the beginning made them male and female,
5 And said ‘For this cause shall a man leave father and mother, and hold fast to his wife: and the two shall become one flesh?’
6 They are no longer two, but one flesh. Therefore what God has joined together, let not man separate.”
7 They say to him “Then why did Moses command us to give divorce papers and to send her away?”
8 He said “Because of the hardness of your hearts Moses allowed you to put away your wives: but from the beginning it was not so.
9 And I say to you whoever divorces his wife, except for fornication, and marries another, commits adultery: and whoever marries her who is divorced commits adultery.”
10 His disciples said to him “If such is the case of a man with his wife, it is not good to marry.”
11 But he said to them “Not everyone can receive this saying, except to whom it is given.
12 For there are some eunuchs who were born from their mother’s womb; and there are some eunuchs who were made by men; and there are eunuchs who have made themselves eunuchs for the kingdom of heaven’s sake. He that is able to receive it, let him receive it.”
13 Then little children were brought to him, that he should put his hands on them, and pray. And the disciples rebuked them.
14 But Jesus said “Let the little children come to me, and do not hinder them. For such is the kingdom of heaven.”
15 And he laid his hands on them, and departed from there.
16 Just then one came and said to him “Good Master, what good thing shall I do, that I may have eternal life?”
17 He said to him “Why do you call me good? There is none good but one, that is, God: but if you would enter into life, keep the commandments.”
18 He asked him “Which ones?” Jesus said “You shall not murder, You shall not commit adultery, You shall not steal, You shalt not bear false witness,
19 Honor your father and your mother: and, You shall love your neighbour as yourself.”
20 The young man said to him “All these things have I kept from my youth: what do I still lack?”
21 Jesus said to him “If you would be perfect, go and sell all that you have, and give to the poor, and you will have treasure in heaven: then come and follow me.”
22 But when the young man heard that saying, he went away sorrowful: for he had great possessions.
23 Then Jesus told his disciples “Truly I say to you that a rich man shall hardly enter into the kingdom of heaven.
24 And again I say to you, it is easier for a camel to go through the eye of a needle, than for a rich man to enter into the kingdom of God.”
25 When his disciples heard it, they were greatly astonished, saying “Who then can be saved?”
26 But Jesus looked at them and said “With man this is impossible, but with God all things are possible.”
27 Then Peter answered and said to him “Behold, we have forsaken all, and followed you? What then will there be for us?”
28 And Jesus said to them “Truly I say to you, that in the regeneration when the Son of Man shall sit on the throne of his glory, you who have followed me will also sit on twelve thrones judging the twelve tribes of Israel.
29 Every one that has forsaken houses, or brothers, or sisters, or father, or mother, or wife, or children, or lands, for my name’s sake, will receive a hundred times as much and inherit everlasting life.
30 But many who are first shall be last; and the last shall be first.
See also: Matthew 19 in ESV, HCSB, NASB, NIV via Bible Gateway.

In v. 28 when Jesus talks about the “regeneration” in which he appears sitting on the throne of his glory, some translations say the new world or something similar. The Holman says Messianic Kingdom. All of these are ways of saying the New Heaven and New Earth after the former things have passed away.
That’s one of those mental notes I had while reading through the text that never made it into my actual notes. It happens a lot.