Genesis 38:12-15

Now after a considerable time Shua’s daughter, the wife of Judah, died; and when the time of mourning was ended, Judah went up to his sheepshearers at Timnah, he and his friend Hirah the Adullamite. It was told to Tamar, “Behold, your father-in-law is going up to Timnah to shear his sheep.” So she removed her widow’s garments and covered herself with a veil, and wrapped herself, and sat in the gateway of Enaim, which is on the road to Timnah; for she saw that Shelah had grown up, and she had not been given to him as a wife. When Judah saw her, he thought she was a harlot, for she had covered her face.