The story of the rape of Tamar by her half brother Amnon and the revenge taken against Amnon by Tamar’s full brother Absalom cannot be read apart from some of the details of the palace and family politics that the narrative takes for granted. According to 2 Sam. 3:2, Amnon was David’s ﬁrst son (by Ahinoam). We know of David’s second son (by Abigail) only that he was called Chileab in 2 Sam. 3:3 and Daniel in 1 Chron. 3:1; he ﬁgures in no narrative.
Absalom is David’s third son. His mother Maacah is royal, the daughter of a Transjordanian king, Talmai, king of Geshur; (2 Sam. 3:3 ); Tamar is his full sister (2 Sam. 13:1). Jonadab, Amnon’s adviser in the affair, is him-self a member of the family—a nephew of David and so first cousin to the other three (13:3).
Whatever justiﬁcation Absalom might have claimed for killing Amnon, such as Amnon’s rape of Tamar, Absalom’s own royal ambitions are not hurt by having Amnon out of the way. Indeed, as soon as Absalom is admitted back into the royal household following his murder of Amnon and subsequent flight to his maternal grandfather, he begins to plot his own rule, even while David is still alive and well (2 Sam. 15:1-12).
It has often been pointed out that this narrative is sprinkled liberally with relational words. Absalom is called David’s son in 13:1, and Tamar is Absalom’s sister. Amnon is also called David’s son, and Tamar Amnon’s sister.
Jonadab’s relation to them all is clearly spelled out in v. 3, and he addresses Amnon as ‘son of the king’ in v. 4. In the same verse Amnon refers to Tamar as ‘my brother Absalom’s sister.’
And so it goes, as the narrator emphasizes the intertwining relationships in this polygynous family.
It is Jonadab who puts the idea into Amnon’s head that there is a way to be alone with Tamar with David’s blessing, by pretending to be ill. The narrative report of Jonadab’s advice stops short of suggesting rape, but if his recommendation were in any way innocent there would be no need for the deception.
Women’s Bible Commentary, Carol A. Newsom and Sharon H. Ringe, Editors, Westminster John Knox Press, Louisville, p.99.