The names and testimonies of David, Caleb, Zerubbabel, and Jabez are singled out by Ezra in order to remind Israel of the kinds of people God used in history. They were the minority, but God used a shepherd to kill a giant. They felt cursed, but God restored cursed families before. They didn't know how to pray, but their ancestors did.
1. The lives of David and Elijah prove God always works most through a faithful minority.
2. The curse of Jeconiah proved that God doesn't hold grudges since Zerubbabel broke that chain.
3. Jabez proved that God can bless a life that chooses Him regardless of having everything else against them.