בראשית, פרק ל״ח, פסוק י״ט

Following her encounter with Judah, Tamar steps out of her temporary disguise and swiftly returns to her former status. She takes the veil off her head and face [רד״ק], shedding the brief identity she had assumed. This rapid change of clothing is much more than a practical step. It acts as clear proof of her true inner motives and the single purpose behind her actions.

The primary approach among commentators is that her immediate return to the garments of a widow shows her pure intentions. Her only goal was to conceive a child specifically from Judah. By doing so, she accomplished exactly what she set out to do. She secured her levirate marriage and changed her future from a childless widow to a mother within this specific household [ביאור שטיינזלץ].

Her intense drive to remain bound to Judah's family stemmed from a widespread desire to be part of the lineage of his father, Abraham [רד״ק]. Having successfully conceived the child she sought, she had absolutely no interest in marrying anyone else outside of this chosen family. Because her mission was complete, she immediately put her widow's garments back on [ספורנו].