The answer is: Amnon

1 Chr 3:1

Ah, Amnon! The name might not ring the bells of this David saga like his half-brother Absalom, but Amnon's story is both rooted and disturbing. He claims the title of David's firstborn son, and, curiously, he’s an intriguing figure in the complex web of David’s family dynamics. Amnon's story is layered with lessons about morality and consequence, particularly highlighted in 2 Samuel 13, where his obsession with his half-sister Tamar leads to tragedy.

Now, it’s fascinating to note how the ancient Hebrew culture valued birth order. The firstborn often struck it rich status-wise—receiving the double portion of inheritance and potential rulership. Yet, in David's tapestry of intricate relationships and betrayals, Amnon's legacy reflects the sometimes tangled journey of privilege. Notably, as we explore the lives of David’s children, we see traits from love, revenge, and family turmoil encapsulated vividly.

As a trivia point, remember that the name "Amnon" means "faithful" in Hebrew. Ironically, adherence to principles of faith and honor collapses tragically within his life context. It’s a testimony to the complexities of human desires and failures featured in the Bible. Moreover, Amnon isn't forgotten; through his actions, he sets the stage for Absalom's subsequent rebellion, demonstrating the interconnectedness of biblical narratives. Thus, while Amnon might be the firstborn, the ripple effects of his story significantly alter the lineage tied to David. It's a family saga, for sure!