What does Matthew 10:42 mean?
Jesus is sending out His twelve apostles to carry His message to the people of Israel and, eventually, to the world. They will teach and do miracles in Jesus' name and under His power and authority. They will represent Jesus so thoroughly that any who receives an apostle will be receiving both Jesus and the one who sent Him. Such people will share in the rewards to be given to the apostles.Now Jesus describes part of what it means to receive one of His disciples, whom He calls "little ones." The person who gives one of them a cup of cold water—because he is a disciple of Jesus—will not lose his or her reward of being included in the kingdom of heaven. The implication is that those who serve Jesus' disciples because they believe in Jesus and want to help the mission succeed will be rewarded.
Even in Jesus' time, people preferred to drink cold water. A cup of cold water, if available, was not expensive. Even a very poor person could help the mission of Jesus by offering His workers some cold water along the way. Wealth and status are no barrier to serving Jesus' mission by giving assistance to His laborers.
Matthew 10:40–42 closes out Jesus' instructions to the apostles, as He sends them first to the people of Israel. He says any who receive the apostles, believing their message about Jesus, will also be receiving Him and the One who sent Him. They will share in the apostles' reward, as those who receive a prophet or righteous person share in their rewards. Those who give a cup of cold water to one of "these little ones," in this case meaning the apostles, will not lose their reward of eternity in the kingdom of heaven.
Jesus gives His authority over disease, demons, and even death to His twelve hand-picked apostles. He gives them instructions in preparation both for a short-term trip to the towns of Galilee and their ministry after He has left the earth. First, they will preach His message of the kingdom in Israelite towns as they heal and cast out demons to demonstrate His power. Later, they will suffer great persecution as they represent Him before both Jews and Gentiles. They should not be afraid, though, and trust their Father to be with them and to reward them.