2 Samuel 19:13

And say ye to Amasa, Art thou not of my bone, and of my flesh? God do so to me, and more also, if thou be not captain of the host before me continually in the room of Joab.

2 Samuel 19:13 belongs to the account of David's victory over Absalom and his return to Jerusalem, standing within the longer history of the war between the house of Saul and the house of David that continues through 2 Samuel 20. It belongs to the closing history of David's reign, which recounts his difficulties, the sad results of his many wives and his inability to control his sons, Absalom's rebellion and death, David's lament and return to Jerusalem, his troubles with Joab, and his numbering of the people. The detailed faithfulness of that telling marks it as inspired and shows that God does not conceal the sins even of the greatest kings.

The verse records David appealing to his kinship with Amasa, as bone and flesh, to secure his loyalty, appointing him captain of the host continually in the room of Joab and binding the promise with a solemn oath. It belongs to the later history of David that displays the judgments that followed his great transgression in the matter of Uriah, fulfilling Nathan's prophetic denunciation. It is part of the retribution that followed David's wicked conduct toward Uriah, especially in troubles within his own family, showing that wrongdoing brings consequences of its own kind.

That retribution followed David through all the rest of his life, principally in his own family, and together with the history of Amnon and Tamar, the rebellion and unnatural crimes of Absalom, and Adonijah's rebellion and death, it shows that David received back in kind for the wrongs he committed. What a man sows, that he shall reap, and sin never pays except in its own kind.