Because
2 Samuel 19:12
Ye are my brethren, ye are my bones and my flesh: wherefore then are ye the last to bring back the king?
2 Samuel 5:1
Then came all the tribes of Israel to David unto Hebron, and spake, saying, Behold, we are thy bone and thy flesh.
1 Chronicles 2:3-17
3
The sons of Judah; Er, and Onan, and Shelah: which three were born unto him of the daughter of Shua the Canaanitess. And Er, the firstborn of Judah, was evil in the sight of the LORD; and he slew him.
4
And Tamar his daughter in law bare him Pharez and Zerah. All the sons of Judah were five.
5
The sons of Pharez; Hezron, and Hamul.
6
And the sons of Zerah; Zimri, and Ethan, and Heman, and Calcol, and Dara: five of them in all.
7
And the sons of Carmi; Achar, the troubler of Israel, who transgressed in the thing accursed.
8
And the sons of Ethan; Azariah.
9
The sons also of Hezron, that were born unto him; Jerahmeel, and Ram, and Chelubai.
10
And Ram begat Amminadab; and Amminadab begat Nahshon, prince of the children of Judah;
11
And Nahshon begat Salma, and Salma begat Boaz,
12
And Boaz begat Obed, and Obed begat Jesse,
13
And Jesse begat his firstborn Eliab, and Abinadab the second, and Shimma the third,
14
Nethaneel the fourth, Raddai the fifth,
15
Ozem the sixth, David the seventh:
16
Whose sisters were Zeruiah, and Abigail. And the sons of Zeruiah; Abishai, and Joab, and Asahel, three.
17
And Abigail bare Amasa: and the father of Amasa was Jether the Ishmeelite.