What does Matthew 1:5 mean?

Matthew has followed the line of Jesus from Abraham to a man named Salmon. Salmon fathered a man named Boaz by a woman named Rahab. This is the second woman mentioned in Matthew's genealogy of Jesus. She was also, remarkably, a Gentile. Her famous story is told in Joshua 2. Rahab was a prostitute living in the town of Jericho who protected Israel's spies because of her confidence in Israel's God. In exchange, Joshua spared her life when the Israelites destroyed Jericho and he allowed her to live among the people of Israel after they had occupied the Promised Land (Joshua 6:25). Though Rahab was known as "Rahab the prostitute," she is also praised in both Hebrews 11:31 and James 2:25 for her faith in God.

Matthew is clearly not interested in protecting the reputation of Jesus' human ancestry. In fact, he seems to go out of his way to show that Jesus is a true son of Israel—from the most to least reputable among them. Though Jesus never sinned, the Bible never suggests the human line He was born into was any more or less sinful than the rest of humanity. Jesus came to die for sinners (Hebrews 4:15–16).

Salmon and Rahab had a son named Boaz, who married another Gentile, a Moabite woman named Ruth. Their much-loved romantic story is told in the book of Ruth. Their son Obed became the father of Jesse, the father of Israel's beloved King David.