The answer is: To appear as a prostitute

Genesis 38:14-15 - Tamar veiled herself and dressed as a prostitute to deceive Judah into fulfilling his duty to provide her with an heir. This story, though complex, ultimately leads to the lineage of David and Jesus.

Tamar’s creative yet risky plan definitely reveals intriguing layers of societal norms and personal agency in the ancient Hebrew world. By donning the attire of a prostitute, Tamar was not merely trying to fool Judah; she was making a deliberate choice within an oppressive situation. When a woman's rights and position could hinge upon male family members (in this case, Judah), the actions Tamar took—bold and rightfully strategic—become key to unraveling her difficult plight.

Interestingly, the act of disguise and deception isn't just a standalone incident in the Bible. It echoes through other stories, from Jacob’s disguise to get his father Isaac’s blessing to Esther’s strategy to save her people. Safeguarding her future while securing a lineage was Tamar's way of working within—and pushing against—the system she lived in. Can we blame her for taking command of her narrative?

More trivia? The final twist comes with her being part of the genealogy of Jesus as detailed in the Gospel of Matthew. Tamar—whose story was buried in shame and secrecy—exudes remarkable resilience. If we track family lines, sometimes it’s not just the noble or virtuous we celebrate; it’s the unexpected heroes, too. Her story teaches us that appearances can be deceiving, and even in the most challenging situations, extraordinary resilience can lead to legacy. So, Tamar's journey doesn't stay shrouded in shadows; it illuminates the path to kings and, ultimately, the embodiment of hope for many.