Genesis 38:12-16

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.

And Tamar was told, “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 assumed she was a prostitute, for she had covered her face.

So he turned aside to her by the road, and said, “Here now, let me have relations with you”; for he did not know that she was his daughter-in-law. And she said, “What will you give me, that you may have relations with me?”