There are two women named Tamar mentioned in Scripture. Both are tragic figures, women who were ruined by the neglect and abuse of close family members. Their stories seem to be included in Scripture for the purpose of providing historical and spiritual information about the Messianic line.
Jacob’s son Judah (patriarch of the line of Judah) had three sons: Er, Onan and Shelah. A woman named Tamar married Er, but then Er died, leaving her a widow. Since it was required that the next of kin care for a brother’s widow, Tamar was given to Onan, but he also died. Shelah was still a boy and could not marry Tamar, so Judah asked her to return to her father’s house and wait until Shelah was grown up. However, once Shelah was old enough, Judah did not honor his promise. Tamar then went into town disguised as a prostitute, tricked Judah, and got him to sleep with her. She then became pregnant and bore twin sons named Perez and Zerah.
The other Tamar was King David’s daughter. She had a brother, Absalom, and a half-brother, Amnon. Amnon had an obsessive desire for his half-sister Tamar, and one day he pretended to be sick and called for her to come to him in his bedroom to help him. When she was there alone with him, he raped her. Unfortunately, though David was angry, he did not punish Amnon or require him to marry Tamar, so Absalom took it upon himself to murder Amnon in revenge (2 Sam. 13:1-22). Absalom’s anger and bitterness towards his father because of these events eventually led to his attempt to usurp his throne and to disgrace David by committing public immorality with his father’s concubines.
We would expect the twin sons of Judah’s incestuous union with his daughter-in-law to be outcasts, hidden away, or perhaps not even mentioned. However, surprisingly, the Messianic line continues through Tamar’s son Perez. God did not provide a “cleaner” way to continue the line that would eventually include His Son. Perez was the ancestor of Jesus of Nazereth.
It is the same with King David. Absalom’s anger and rejection of his father’s rule seems to have been born out of a festering bitterness towards David. Though Absalom was clearly in the wrong for the murder of Amnon, we sympathize with him, and we sympathize with his disgraced sister. Considering David’s own immorality and the murder he committed, it is easy to see why Absalom thought himself the better man. But despite David’s faults, God still chose to continue the line of the Messiah through David rather than through Absalom.
Why are these unpleasant stories included in Scripture, and why are the people involved – people who hurt others, even their own family members – granted the privilege of being included in the Messianic line? It may be simply to show us that God’s purpose is accomplished despite man’s unrighteousness. In Hebrews 11 there is a long list of Old Testament people who are commended for their faith, and among them are many sinful people who did dreadful things. But because they believed God, their faith was credited to them as righteousness (Genesis 15:6).